The introduction of functional (usually cloned) GENES into cells. A variety of techniques and naturally occurring processes are used for the gene transfer such as cell hybridization, LIPOSOMES or microcell-mediated gene transfer, ELECTROPORATION, chromosome-mediated gene transfer, TRANSFECTION, and GENETIC TRANSDUCTION. Gene transfer may result in genetically transformed cells and individual organisms.
The naturally occurring transmission of genetic information between organisms, related or unrelated, circumventing parent-to-offspring transmission. Horizontal gene transfer may occur via a variety of naturally occurring processes such as GENETIC CONJUGATION; GENETIC TRANSDUCTION; and TRANSFECTION. It may result in a change of the recipient organism's genetic composition (TRANSFORMATION, GENETIC).
DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.
Techniques and strategies which include the use of coding sequences and other conventional or radical means to transform or modify cells for the purpose of treating or reversing disease conditions.
NEURONS in the inner nuclear layer of the RETINA that synapse with both the RETINAL PHOTORECEPTOR CELLS and the RETINAL BIPOLAR CELLS, as well as other horizontal cells. The horizontal cells modulate the sensory signal.
A family of non-enveloped viruses infecting mammals (MASTADENOVIRUS) and birds (AVIADENOVIRUS) or both (ATADENOVIRUS). Infections may be asymptomatic or result in a variety of diseases.
The transfer of bacterial DNA by phages from an infected bacterium to another bacterium. This also refers to the transfer of genes into eukaryotic cells by viruses. This naturally occurring process is routinely employed as a GENE TRANSFER TECHNIQUE.
The relationships of groups of organisms as reflected by their genetic makeup.
A genus of the family PARVOVIRIDAE, subfamily PARVOVIRINAE, which are dependent on a coinfection with helper adenoviruses or herpesviruses for their efficient replication. The type species is Adeno-associated virus 2.
The transfer of mammalian embryos from an in vivo or in vitro environment to a suitable host to improve pregnancy or gestational outcome in human or animal. In human fertility treatment programs, preimplantation embryos ranging from the 4-cell stage to the blastocyst stage are transferred to the uterine cavity between 3-5 days after FERTILIZATION IN VITRO.
Family of RNA viruses that infects birds and mammals and encodes the enzyme reverse transcriptase. The family contains seven genera: DELTARETROVIRUS; LENTIVIRUS; RETROVIRUSES TYPE B, MAMMALIAN; ALPHARETROVIRUS; GAMMARETROVIRUS; RETROVIRUSES TYPE D; and SPUMAVIRUS. A key feature of retrovirus biology is the synthesis of a DNA copy of the genome which is integrated into cellular DNA. After integration it is sometimes not expressed but maintained in a latent state (PROVIRUSES).
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Genes that are introduced into an organism using GENE TRANSFER TECHNIQUES.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
The genetic complement of a BACTERIA as represented in its DNA.
A parasexual process in BACTERIA; ALGAE; FUNGI; and ciliate EUKARYOTA for achieving exchange of chromosome material during fusion of two cells. In bacteria, this is a uni-directional transfer of genetic material; in protozoa it is a bi-directional exchange. In algae and fungi, it is a form of sexual reproduction, with the union of male and female gametes.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
A technique in which electric pulses of intensity in kilovolts per centimeter and of microsecond-to-millisecond duration cause a temporary loss of the semipermeability of CELL MEMBRANES, thus leading to ion leakage, escape of metabolites, and increased uptake by cells of drugs, molecular probes, and DNA.
Change in learning in one situation due to prior learning in another situation. The transfer can be positive (with second learning improved by first) or negative (where the reverse holds).
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
A genus of the family RETROVIRIDAE consisting of non-oncogenic retroviruses that produce multi-organ diseases characterized by long incubation periods and persistent infection. Lentiviruses are unique in that they contain open reading frames (ORFs) between the pol and env genes and in the 3' env region. Five serogroups are recognized, reflecting the mammalian hosts with which they are associated. HIV-1 is the type species.
The functional hereditary units of BACTERIA.
The genetic unit consisting of three structural genes, an operator and a regulatory gene. The regulatory gene controls the synthesis of the three structural genes: BETA-GALACTOSIDASE and beta-galactoside permease (involved with the metabolism of lactose), and beta-thiogalactoside acetyltransferase.
A type of FLUORESCENCE SPECTROSCOPY using two FLUORESCENT DYES with overlapping emission and absorption spectra, which is used to indicate proximity of labeled molecules. This technique is useful for studying interactions of molecules and PROTEIN FOLDING.
Form of passive immunization where previously sensitized immunologic agents (cells or serum) are transferred to non-immune recipients. When transfer of cells is used as a therapy for the treatment of neoplasms, it is called adoptive immunotherapy (IMMUNOTHERAPY, ADOPTIVE).
Proteins found in any species of bacterium.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
Elements of limited time intervals, contributing to particular results or situations.
Voluntary or reflex-controlled movements of the eye.
The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.
Deoxyribonucleic acid that makes up the genetic material of bacteria.
Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.
Proteins which are involved in the phenomenon of light emission in living systems. Included are the "enzymatic" and "non-enzymatic" types of system with or without the presence of oxygen or co-factors.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Interfacility or intrahospital transfer of patients. Intrahospital transfer is usually to obtain a specific kind of care and interfacility transfer is usually for economic reasons as well as for the type of care provided.
A ubiquitous family of proteins that transport PHOSPHOLIPIDS such as PHOSPHATIDYLINOSITOL and PHOSPHATIDYLCHOLINE between membranes. They play an important role in phospholipid metabolism during vesicular transport and SIGNAL TRANSDUCTION.
The blending of separate images seen by each eye into one composite image.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
A common name for fish of the family Percidae, belonging to the suborder Percoidei, order PERCIFORMES.
Established cell cultures that have the potential to propagate indefinitely.
Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.
The turning inward of the lines of sight toward each other.
The genetic complement of an archaeal organism (ARCHAEA) as represented in its DNA.
Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.
A reflex wherein impulses are conveyed from the cupulas of the SEMICIRCULAR CANALS and from the OTOLITHIC MEMBRANE of the SACCULE AND UTRICLE via the VESTIBULAR NUCLEI of the BRAIN STEM and the median longitudinal fasciculus to the OCULOMOTOR NERVE nuclei. It functions to maintain a stable retinal image during head rotation by generating appropriate compensatory EYE MOVEMENTS.
An Ig superfamily transmembrane protein that localizes to junctional complexes that occur between ENDOTHELIAL CELLS and EPTHELIAL CELLS. The protein may play a role in cell-cell adhesion and is the primary site for the attachment of ADENOVIRUSES during infection.
Factor derived from leukocyte lysates of immune donors which can transfer both local and systemic cellular immunity to nonimmune recipients.
The muscles that move the eye. Included in this group are the medial rectus, lateral rectus, superior rectus, inferior rectus, inferior oblique, superior oblique, musculus orbitalis, and levator palpebrae superioris.
The functional genetic units of ARCHAEA.
Genes whose expression is easily detectable and therefore used to study promoter activity at many positions in a target genome. In recombinant DNA technology, these genes may be attached to a promoter region of interest.
Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.
A peptide which is a homopolymer of lysine.
The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.
The difference between two images on the retina when looking at a visual stimulus. This occurs since the two retinas do not have the same view of the stimulus because of the location of our eyes. Thus the left eye does not get exactly the same view as the right eye.
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Common name for Carassius auratus, a type of carp (CARPS).
Proteins that bind to and transfer CHOLESTEROL ESTERS between LIPOPROTEINS such as LOW-DENSITY LIPOPROTEINS and HIGH-DENSITY LIPOPROTEINS.
Strongly cationic polymer that binds to certain proteins; used as a marker in immunology, to precipitate and purify enzymes and lipids. Synonyms: aziridine polymer; Epamine; Epomine; ethylenimine polymer; Montrek; PEI; Polymin(e).
Methods of implanting a CELL NUCLEUS from a donor cell into an enucleated acceptor cell.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Awareness of oneself in relation to time, place and person.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Cells lacking a nuclear membrane so that the nuclear material is either scattered in the cytoplasm or collected in a nucleoid region.
The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)
One of the three domains of life (the others being BACTERIA and Eukarya), formerly called Archaebacteria under the taxon Bacteria, but now considered separate and distinct. They are characterized by: (1) the presence of characteristic tRNAs and ribosomal RNAs; (2) the absence of peptidoglycan cell walls; (3) the presence of ether-linked lipids built from branched-chain subunits; and (4) their occurrence in unusual habitats. While archaea resemble bacteria in morphology and genomic organization, they resemble eukarya in their method of genomic replication. The domain contains at least four kingdoms: CRENARCHAEOTA; EURYARCHAEOTA; NANOARCHAEOTA; and KORARCHAEOTA.
Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. (Adams et al., Principles of Neurology, 6th ed, p272)
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
Three long canals (anterior, posterior, and lateral) of the bony labyrinth. They are set at right angles to each other and are situated posterosuperior to the vestibule of the bony labyrinth (VESTIBULAR LABYRINTH). The semicircular canals have five openings into the vestibule with one shared by the anterior and the posterior canals. Within the canals are the SEMICIRCULAR DUCTS.
The positioning and accommodation of eyes that allows the image to be brought into place on the FOVEA CENTRALIS of each eye.
The rate dynamics in chemical or physical systems.
The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.
Distinct units in some bacterial, bacteriophage or plasmid GENOMES that are types of MOBILE GENETIC ELEMENTS. Encoded in them are a variety of fitness conferring genes, such as VIRULENCE FACTORS (in "pathogenicity islands or islets"), ANTIBIOTIC RESISTANCE genes, or genes required for SYMBIOSIS (in "symbiosis islands or islets"). They range in size from 10 - 500 kilobases, and their GC CONTENT and CODON usage differ from the rest of the genome. They typically contain an INTEGRASE gene, although in some cases this gene has been deleted resulting in "anchored genomic islands".
Voluntary or involuntary motion of head that may be relative to or independent of body; includes animals and humans.
Involuntary rhythmical movements of the eyes in the normal person. These can be naturally occurring as in end-position (end-point, end-stage, or deviational) nystagmus or induced by the optokinetic drum (NYSTAGMUS, OPTOKINETIC), caloric test, or a rotating chair.
Photosensitive afferent neurons located primarily within the FOVEA CENTRALIS of the MACULA LUTEA. There are three major types of cone cells (red, blue, and green) whose photopigments have different spectral sensitivity curves. Retinal cone cells operate in daylight vision (at photopic intensities) providing color recognition and central visual acuity.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
Surgical procedure by which a tendon is incised at its insertion and placed at an anatomical site distant from the original insertion. The tendon remains attached at the point of origin and takes over the function of a muscle inactivated by trauma or disease.
Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
Directed modification of the gene complement of a living organism by such techniques as altering the DNA, substituting genetic material by means of a virus, transplanting whole nuclei, transplanting cell hybrids, etc.
A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)
An abrupt voluntary shift in ocular fixation from one point to another, as occurs in reading.
Enzymes that oxidize certain LUMINESCENT AGENTS to emit light (PHYSICAL LUMINESCENCE). The luciferases from different organisms have evolved differently so have different structures and substrates.
Misalignment of the visual axes of the eyes. In comitant strabismus the degree of ocular misalignment does not vary with the direction of gaze. In noncomitant strabismus the degree of misalignment varies depending on direction of gaze or which eye is fixating on the target. (Miller, Walsh & Hoyt's Clinical Neuro-Ophthalmology, 4th ed, p641)
High molecular weight insoluble polymers which contain functional anionic groups that are capable of undergoing exchange reactions with cations.
Common name for a number of different species of fish in the family Cyprinidae. This includes, among others, the common carp, crucian carp, grass carp, and silver carp.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Perception of three-dimensionality.
Copies of transposable elements interspersed throughout the genome, some of which are still active and often referred to as "jumping genes". There are two classes of interspersed repetitive elements. Class I elements (or RETROELEMENTS - such as retrotransposons, retroviruses, LONG INTERSPERSED NUCLEOTIDE ELEMENTS and SHORT INTERSPERSED NUCLEOTIDE ELEMENTS) transpose via reverse transcription of an RNA intermediate. Class II elements (or DNA TRANSPOSABLE ELEMENTS - such as transposons, Tn elements, insertion sequence elements and mobile gene cassettes of bacterial integrons) transpose directly from one site in the DNA to another.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Normal nystagmus produced by looking at objects moving across the field of vision.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
The transmission of infectious disease or pathogens. When transmission is within the same species, the mode can be horizontal or vertical (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).
Transport proteins that carry specific substances in the blood or across cell membranes.
Proteins prepared by recombinant DNA technology.
Species of the genus MASTADENOVIRUS, causing a wide range of diseases in humans. Infections are mostly asymptomatic, but can be associated with diseases of the respiratory, ocular, and gastrointestinal systems. Serotypes (named with Arabic numbers) have been grouped into species designated Human adenovirus A-F.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
Introduction of substances into the body using a needle and syringe.
Progenitor cells from which all blood cells derive.
Genomes of temperate BACTERIOPHAGES integrated into the DNA of their bacterial host cell. The prophages can be duplicated for many cell generations until some stimulus induces its activation and virulence.
The sequential location of genes on a chromosome.
Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.
The integration of exogenous DNA into the genome of an organism at sites where its expression can be suitably controlled. This integration occurs as a result of homologous recombination.
One of the three domains of life (the others being BACTERIA and ARCHAEA), also called Eukarya. These are organisms whose cells are enclosed in membranes and possess a nucleus. They comprise almost all multicellular and many unicellular organisms, and are traditionally divided into groups (sometimes called kingdoms) including ANIMALS; PLANTS; FUNGI; and various algae and other taxa that were previously part of the old kingdom Protista.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
Change brought about to an organisms genetic composition by unidirectional transfer (TRANSFECTION; TRANSDUCTION, GENETIC; CONJUGATION, GENETIC, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell's genome.
Acceleration produced by the mutual attraction of two masses, and of magnitude inversely proportional to the square of the distance between the two centers of mass. It is also the force imparted by the earth, moon, or a planet to an object near its surface. (From NASA Thesaurus, 1988)
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
The heritable modification of the properties of a competent bacterium by naked DNA from another source. The uptake of naked DNA is a naturally occuring phenomenon in some bacteria. It is often used as a GENE TRANSFER TECHNIQUE.
Viruses whose hosts are bacterial cells.
A family of freshwater fish comprising the minnows or CARPS.
A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.
The systematic study of the complete DNA sequences (GENOME) of organisms.
A class of enzymes that inactivate aminocyclitol-aminoglycoside antibiotics (AMINOGLYCOSIDES) by regiospecific PHOSPHORYLATION of the 3' and/or 5' hydroxyl.
Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.
Genotypic differences observed among individuals in a population.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.
Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.
Storage-stable blood coagulation factor acting in the intrinsic pathway. Its activated form, IXa, forms a complex with factor VIII and calcium on platelet factor 3 to activate factor X to Xa. Deficiency of factor IX results in HEMOPHILIA B (Christmas Disease).
An oval, bony chamber of the inner ear, part of the bony labyrinth. It is continuous with bony COCHLEA anteriorly, and SEMICIRCULAR CANALS posteriorly. The vestibule contains two communicating sacs (utricle and saccule) of the balancing apparatus. The oval window on its lateral wall is occupied by the base of the STAPES of the MIDDLE EAR.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
The properties, processes, and behavior of biological systems under the action of mechanical forces.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
A synthetic polymer which agglutinates red blood cells. It is used as a heparin antagonist.
The position or attitude of the body.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
An enzyme that catalyzes the conversion of ATP and thymidine to ADP and thymidine 5'-phosphate. Deoxyuridine can also act as an acceptor and dGTP as a donor. (From Enzyme Nomenclature, 1992) EC 2.7.1.21.
Forceful administration into a muscle of liquid medication, nutrient, or other fluid through a hollow needle piercing the muscle and any tissue covering it.
A deficiency of blood coagulation factor IX inherited as an X-linked disorder. (Also known as Christmas Disease, after the first patient studied in detail, not the holy day.) Historical and clinical features resemble those in classic hemophilia (HEMOPHILIA A), but patients present with fewer symptoms. Severity of bleeding is usually similar in members of a single family. Many patients are asymptomatic until the hemostatic system is stressed by surgery or trauma. Treatment is similar to that for hemophilia A. (From Cecil Textbook of Medicine, 19th ed, p1008)
Viruses which enable defective viruses to replicate or to form a protein coat by complementing the missing gene function of the defective (satellite) virus. Helper and satellite may be of the same or different genus.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
Enzymes that recombine DNA segments by a process which involves the formation of a synapse between two DNA helices, the cleavage of single strands from each DNA helix and the ligation of a DNA strand from one DNA helix to the other. The resulting DNA structure is called a Holliday junction which can be resolved by DNA REPLICATION or by HOLLIDAY JUNCTION RESOLVASES.
Self-replicating cytoplasmic organelles of plant and algal cells that contain pigments and may synthesize and accumulate various substances. PLASTID GENOMES are used in phylogenetic studies.
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.
Non-human animals, selected because of specific characteristics, for use in experimental research, teaching, or testing.
Multicellular, eukaryotic life forms of kingdom Plantae (sensu lato), comprising the VIRIDIPLANTAE; RHODOPHYTA; and GLAUCOPHYTA; all of which acquired chloroplasts by direct endosymbiosis of CYANOBACTERIA. They are characterized by a mainly photosynthetic mode of nutrition; essentially unlimited growth at localized regions of cell divisions (MERISTEMS); cellulose within cells providing rigidity; the absence of organs of locomotion; absence of nervous and sensory systems; and an alternation of haploid and diploid generations.
The adjustment of the eye to variations in the intensity of light. Light adaptation is the adjustment of the eye when the light threshold is increased; DARK ADAPTATION when the light is greatly reduced. (From Cline et al., Dictionary of Visual Science, 4th ed)
A form of ocular misalignment characterized by an excessive convergence of the visual axes, resulting in a "cross-eye" appearance. An example of this condition occurs when paralysis of the lateral rectus muscle causes an abnormal inward deviation of one eye on attempted gaze.
Plants of the division Rhodophyta, commonly known as red algae, in which the red pigment (PHYCOERYTHRIN) predominates. However, if this pigment is destroyed, the algae can appear purple, brown, green, or yellow. Two important substances found in the cell walls of red algae are AGAR and CARRAGEENAN. Some rhodophyta are notable SEAWEED (macroalgae).
Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.
A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.
The total area or space visible in a person's peripheral vision with the eye looking straightforward.
A genus of bacteria comprised of a heterogenous group of gram-negative small rods and coccoid forms associated with arthropods. (From Bergey's Manual of Systematic Bacteriology, vol 1, 1984)
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
The common name for all members of the Rajidae family. Skates and rays are members of the same order (Rajiformes). Skates have weak electric organs.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Disorders that feature impairment of eye movements as a primary manifestation of disease. These conditions may be divided into infranuclear, nuclear, and supranuclear disorders. Diseases of the eye muscles or oculomotor cranial nerves (III, IV, and VI) are considered infranuclear. Nuclear disorders are caused by disease of the oculomotor, trochlear, or abducens nuclei in the BRAIN STEM. Supranuclear disorders are produced by dysfunction of higher order sensory and motor systems that control eye movements, including neural networks in the CEREBRAL CORTEX; BASAL GANGLIA; CEREBELLUM; and BRAIN STEM. Ocular torticollis refers to a head tilt that is caused by an ocular misalignment. Opsoclonus refers to rapid, conjugate oscillations of the eyes in multiple directions, which may occur as a parainfectious or paraneoplastic condition (e.g., OPSOCLONUS-MYOCLONUS SYNDROME). (Adams et al., Principles of Neurology, 6th ed, p240)
Cells of the higher organisms, containing a true nucleus bounded by a nuclear membrane.
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.
A phylum of bacteria consisting of the purple bacteria and their relatives which form a branch of the eubacterial tree. This group of predominantly gram-negative bacteria is classified based on homology of equivalent nucleotide sequences of 16S ribosomal RNA or by hybridization of ribosomal RNA or DNA with 16S and 23S ribosomal RNA.
Surgical reinnervation of a denervated peripheral target using a healthy donor nerve and/or its proximal stump. The direct connection is usually made to a healthy postlesional distal portion of a non-functioning nerve or implanted directly into denervated muscle or insensitive skin. Nerve sprouts will grow from the transferred nerve into the denervated elements and establish contact between them and the neurons that formerly controlled another area.
The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.
The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.
A class in the phylum PROTEOBACTERIA comprised mostly of two major phenotypes: purple non-sulfur bacteria and aerobic bacteriochlorophyll-containing bacteria.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
Viruses which lack a complete genome so that they cannot completely replicate or cannot form a protein coat. Some are host-dependent defectives, meaning they can replicate only in cell systems which provide the particular genetic function which they lack. Others, called SATELLITE VIRUSES, are able to replicate only when their genetic defect is complemented by a helper virus.
An increase in the rate of speed.
Injections introduced directly into localized lesions.
The upper part of the human body, or the front or upper part of the body of an animal, typically separated from the rest of the body by a neck, and containing the brain, mouth, and sense organs.
A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.
A gelatinous membrane overlying the acoustic maculae of SACCULE AND UTRICLE. It contains minute crystalline particles (otoliths) of CALCIUM CARBONATE and protein on its outer surface. In response to head movement, the otoliths shift causing distortion of the vestibular hair cells which transduce nerve signals to the BRAIN for interpretation of equilibrium.
Eye movements that are slow, continuous, and conjugate and occur when a fixed object is moved slowly.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Mutant mice homozygous for the recessive gene "nude" which fail to develop a thymus. They are useful in tumor studies and studies on immune responses.
Spread and adoption of inventions and techniques from one geographic area to another, from one discipline to another, or from one sector of the economy to another. For example, improvements in medical equipment may be transferred from industrial countries to developing countries, advances arising from aerospace engineering may be applied to equipment for persons with disabilities, and innovations in science arising from government research are made available to private enterprise.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
The science dealing with the correlation of the physical characteristics of a stimulus, e.g., frequency or intensity, with the response to the stimulus, in order to assess the psychologic factors involved in the relationship.
A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).
Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.
Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.
Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.
Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.
A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.
A form of ocular misalignment where the visual axes diverge inappropriately. For example, medial rectus muscle weakness may produce this condition as the affected eye will deviate laterally upon attempted forward gaze. An exotropia occurs due to the relatively unopposed force exerted on the eye by the lateral rectus muscle, which pulls the eye in an outward direction.
A class of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and esophageal structures. Many species are parasites.
Images seen by one eye.
One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
Mice homozygous for the mutant autosomal recessive gene "scid" which is located on the centromeric end of chromosome 16. These mice lack mature, functional lymphocytes and are thus highly susceptible to lethal opportunistic infections if not chronically treated with antibiotics. The lack of B- and T-cell immunity resembles severe combined immunodeficiency (SCID) syndrome in human infants. SCID mice are useful as animal models since they are receptive to implantation of a human immune system producing SCID-human (SCID-hu) hematochimeric mice.
An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.

A 55-kilodalton immunodominant antigen of Porphyromonas gingivalis W50 has arisen via horizontal gene transfer. (1/2070)

A 55-kDa outer membrane protein of Porphyromonas gingivalis W50 is a significant target of the serum immunoglobulin G antibody response of periodontal disease patients and hence may play an important role in host-bacterium interactions in periodontal disease. The gene encoding the 55-kDa antigen (ragB, for receptor antigen B) was isolated on a 9.5-kb partial Sau3AI fragment of P. gingivalis W50 chromosomal DNA in pUC18 by immunoscreening with a monoclonal antibody to this antigen. The 1.6-kb open reading frame (ORF) encoding RagB was located via subcloning and nested-deletion analysis. Sequence analysis demonstrated the presence of an upstream 3.1-kb ORF (ragA) which is cotranscribed with ragB. A number of genetic characteristics suggest that the ragAB locus was acquired by a horizontal gene transfer event. These include a significantly reduced G+C content relative to that of the P. gingivalis chromosome (42 versus 48%) and the presence of mobility elements flanking this locus in P. gingivalis W50. Furthermore, Southern blotting and PCR analyses showed a restricted distribution of this locus in laboratory and clinical isolates of this bacterium. The association of ragAB+ P. gingivalis with clinical status was examined by PCR analysis of subgingival samples. ragAB+ was not detected in P. gingivalis-positive shallow pockets from periodontal disease patients but was present in 36% of the P. gingivalis-positive samples from deep pockets. These data suggest that the ragAB locus was acquired by certain P. gingivalis strains via horizontal gene transfer and that the acquisition of this locus may facilitate the survival of these strains at sites of periodontal destruction.  (+info)

Horizontal gene transfer among genomes: the complexity hypothesis. (2/2070)

Increasingly, studies of genes and genomes are indicating that considerable horizontal transfer has occurred between prokaryotes. Extensive horizontal transfer has occurred for operational genes (those involved in housekeeping), whereas informational genes (those involved in transcription, translation, and related processes) are seldomly horizontally transferred. Through phylogenetic analysis of six complete prokaryotic genomes and the identification of 312 sets of orthologous genes present in all six genomes, we tested two theories describing the temporal flow of horizontal transfer. We show that operational genes have been horizontally transferred continuously since the divergence of the prokaryotes, rather than having been exchanged in one, or a few, massive events that occurred early in the evolution of prokaryotes. In agreement with earlier studies, we found that differences in rates of evolution between operational and informational genes are minimal, suggesting that factors other than rate of evolution are responsible for the observed differences in horizontal transfer. We propose that a major factor in the more frequent horizontal transfer of operational genes is that informational genes are typically members of large, complex systems, whereas operational genes are not, thereby making horizontal transfer of informational gene products less probable (the complexity hypothesis).  (+info)

Genetic diversity of the streptococcal competence (com) gene locus. (3/2070)

The com operon of naturally transformable streptococcal species contains three genes, comC, comD, and comE, involved in the regulation of competence. The comC gene encodes a competence-stimulating peptide (CSP) thought to induce competence in the bacterial population at a critical extracellular concentration. The comD and comE genes are believed to encode the transmembrane histidine kinase and response regulator proteins, respectively, of a two-component regulator, with the comD-encoded protein being a receptor for CSP. Here we report on the genetic variability of comC and comD within Streptococcus pneumoniae isolates. Comparative analysis of sequence variations of comC and comD shows that, despite evidence for horizontal gene transfer at this locus and the lack of transformability of many S. pneumoniae strains in the laboratory, there is a clear correlation between the presence of a particular comC allele and the cognate comD allele. These findings effectively rule out the possibility that the presence of noncognate comC and comD alleles may be responsible for the inability to induce competence in many isolates and indicate the importance of a functional com pathway in these isolates. In addition, we describe a number of novel CSPs from disease-associated strains of S. mitis and S. oralis. The CSPs from these isolates are much more closely related to those from S. pneumoniae than to most CSPs previously reported from S. mitis and S. oralis, suggesting that these particular organisms may be a potential source of DNA in recombination events generating the mosaic structures commonly reported in genes of S. pneumoniae that are under strong selective pressure.  (+info)

Comparison of the evolutionary dynamics of symbiotic and housekeeping loci: a case for the genetic coherence of rhizobial lineages. (4/2070)

In prokaryotes, lateral gene transfer across chromosomal lineages may be mediated by plasmids, phages, transposable elements, and other accessory DNA elements. However, the importance of such transfer and the evolutionary forces that may restrict gene exchange remain largely unexplored in native settings. In this study, tests of phylogenetic congruence are employed to explore the range of horizontal transfer of symbiotic (sym) loci among distinct chromosomal lineages of native rhizobia, the nitrogen-fixing symbiont of legumes. Rhizobial strains isolated from nodules of several host plant genera were sequenced at three loci: symbiotic nodulation genes (nodB and nodC), the chromosomal housekeeping locus glutamine synthetase II (GSII), and a portion of the 16S rRNA gene. Molecular phylogenetic analysis shows that each locus generally subdivides strains into the same major groups, which correspond to the genera Rhizobium, Sinorhizobium, and Mesorhizobium. This broad phylogenetic congruence indicates a lack of lateral transfer across major chromosomal subdivisions, and it contrasts with previous studies of agricultural populations showing broad transfer of sym loci across divergent chromosomal lineages. A general correspondence of the three rhizobial genera with major legume groups suggests that host plant associations may be important in the differentiation of rhizobial nod and chromosomal loci and may restrict lateral transfer among strains. The second major result is a significant incongruence of nod and GSII phylogenies within rhizobial subdivisions, which strongly suggests horizontal transfer of nod genes among congenerics. This combined evidence for lateral gene transfer within, but not between, genetic subdivisions supports the view that rhizobial genera are "reproductively isolated" and diverge independently. Differences across rhizobial genera in the specificity of host associations imply that the evolutionary dynamics of the symbiosis vary considerably across lineages in native settings.  (+info)

Structural characteristics and possible horizontal transfer of group I introns between closely related plant pathogenic fungi. (5/2070)

We have characterized structural features and the distribution pattern of nuclear group I introns found in ribosomal DNA (rDNA) of closely related plant pathogenic fungi of the family Sclerotiniaceae. Sixteen introns, at two distinct positions in the small-subunit (SSU) and large-subunit (LSU) rDNA, were sequenced and analyzed among the 29 taxa included in the initial screening. Genera found to contain introns were Botrytis, Dumontinia, Encoelia, Grovesinia, Myriosclerotinia, and Sclerotinia. Secondary-structure analyses of the group I introns concluded that all belong to the common IC1 subclass. Interestingly, the SSU rDNA intron from Myriosclerotinia caricisampullacea contains an insertion-like sequence extension which may be a relic of an open reading frame. Incongruent branching patterns of intron-based and rDNA-based (internal transcribed spacer) phylogenetic trees suggest that the fungal host genomes and the group I introns do not share a common evolutionary history. A model to explain how horizontal intron transfers may have occurred among the closely related fungal taxa is proposed.  (+info)

Horizontal transfer of DNA by the uptake of apoptotic bodies. (6/2070)

In this study we have raised the question of whether DNA can be transferred from one cell to another by phagocytosis of apoptotic bodies. We have used integrated copies of the Epstein-Barr virus (EBV) as a marker to follow the fate and expression pattern of apoptotic DNA in the phagocytotic host. Apoptosis was induced in EBV-carrying cell lines by irradiation before cultivation with either human fibroblasts, macrophages, or bovine aortic endothelial cells. Analysis of the expression pattern of EBV-encoded genes was performed by immunofluorescent staining as well as in situ hybridization. Cocultivation of apoptotic bodies from lymphoid cell lines containing integrated but not episomal copies of EBV resulted in expression of the EBV-encoded genes EBER and EBNA1 in the recipient cells at a high frequency. Fluorescence in situ hybridization analysis showed uptake of human chromatin as well as integrated EBV-DNA into the nuclei of bovine aortic endothelial cells. These data show that DNA may be rescued and reused from apoptotic bodies by somatic cells. In addition, our findings suggest that apoptotic bodies derived from EBV-carrying B lymphocytes may serve as the source of viral transfer to cells that lack receptors for the EBV virus in vivo.  (+info)

A comparison of the kinetics of plasmid transfer in the conjugation systems encoded by the F plasmid from Escherichia coli and plasmid pCF10 from Enterococcus faecalis. (7/2070)

Quantitative measurements of horizontal DNA transfer are critical if one wishes to address questions relating to ecology, evolution and the safe use of recombinant bacteria. Traditionally, the efficiency of a conjugation system has been described by its transfer frequency. However, transfer frequencies can be determined in many ways and may be sensitive to physical, chemical and biological conditions. In this study the authors have used the mechanistic similarity between bacterial conjugation and simple enzyme catalysis in order to calculate the maximal conjugation rate (Vmax) and the recipient concentration (K(m)) at which the conjugation rate is half its maximal value, for two different conjugation systems: the F plasmid from Escherichia coli and plasmid pCF10 from Enterococcus faecalis. The results are compared with the data obtained from the aggregation-mediated conjugation system encoded on pXO16 from Bacillus thuringiensis. The conjugation systems analysed are fundamentally different; however, they have some characteristics in common: they are able to sustain conjugative transfer in liquid medium and the transfer efficiencies are very high. Conjugation encoded by the F plasmid in E. coli involves the formation of small aggregates (2-20 cells), established by sex pili, and the plasmid's maximal conjugation rate was estimated to be approximately 0.15 transconjugants per donor per minute. Pheromone-induced conjugation in Ent. faecalis, which involves the formation of large aggregates, was found to proceed at a maximal conjugation rate of 0.29 transconjugants per donor per minute. Also, the K(m) value differed significantly between these conjugation systems; this may reflect the inherent differences in mating pair formation and transfer mechanisms. In these conjugation systems, the donors underwent a 'recovery period' between rounds of conjugative transfer and newly formed transconjugants required a period of about 40-80 min to mature into proficient donors.  (+info)

Horizontal gene transfer in glycosyl hydrolases inferred from codon usage in Escherichia coli and Bacillus subtilis. (8/2070)

Glycosyl hydrolase (GH) genes from Escherichia coli and Bacillus subtilis were used to search for cases of horizontal gene transfer. Such an event was inferred by G + C content, codon usage analysis, and a phylogenetic congruency test. The codon usage analysis used is a procedure based on a distance derived from a Pearson linear correlation coefficient determined from a pairwise codon usage comparison. The distances are then used to generate a distance-based tree with which we can define clusters and rapidly compare codon usage. Three genes (yagH from E. coli and xynA and xynB from B. subtilis) were determined to have arrived by horizontal gene transfer and were located in E. coli CP4-6 prophage, and B. subtilis prophages 6 and 5, respectively. In this study, we demonstrate that with codon usage analysis, the proposed horizontally transferred genes can be distinguished from highly expressed genes.  (+info)

Background Polyketides are natural products with a wide range of biological functions and pharmaceutical applications. Discovery and utilization of polyketides can be facilitated by understanding the evolutionary processes that gave rise to the biosynthetic machinery and the natural product potential of extant organisms. Gene duplication and subfunctionalization, as well as horizontal gene transfer are proposed mechanisms in the evolution of biosynthetic gene clusters. To explain the amount of homology in some polyketide synthases in unrelated organisms such as bacteria and fungi, interkingdom horizontal gene transfer has been evoked as the most likely evolutionary scenario. However, the origin of the genes and the direction of the transfer remained elusive. Methodology/Principal Findings We used comparative phylogenetics to infer the ancestor of a group of polyketide synthase genes involved in antibiotic and mycotoxin production. We aligned keto synthase domain sequences of all available fungal 6
Ureaplasma parvum and Ureaplasma urealyticum are sexually transmitted, opportunistic pathogens of the human urogenital tract. There are 14 known serovars distributed between the two species. For decades, it has been postulated based upon limited data that virulence is related to serotype specificity. The results were often inconclusive due to the small sample size and extensive cross-reactivity between certain serovars. We developed real-time quantitative PCRs that allow reliable differentiation of the two species and type strains of each of the 14 serovars. To investigate species and serovar distributions, we typed 1,061 clinical isolates of human ureaplasmas from diverse patient populations. There was only a tenuous association between individual Ureaplasma serovars and certain patient populations. This may in part be explained by the fact that almost 40% of the isolates were genetic mosaics, apparently arising from the recombination of multiple serovars. This explains the extensive ...
Horizontal gene transfer was first described in Japan in a 1959 publication that demonstrated the transfer of antibiotic resistance between different species of bacteria.[4][5] In the mid-1980s, Syvanen suggested that lateral gene transfer not only had biological significance, but was involved in shaping evolutionary history from the beginning of life on Earth.[6] Increasingly, studies of genes and genomes are indicating that considerable horizontal transfer has occurred between prokaryotes.[7][8] The phenomenon appears to have had some significance for unicellular eukaryotes as well. As Bapteste et al. observe, additional evidence suggests that gene transfer might also be an important evolutionary mechanism in protist evolution.[9] There is some evidence that even higher plants and animals have been affected. Richardson and Palmer (2007) state: Horizontal gene transfer (HGT) has played a major role in bacterial evolution and is fairly common in certain unicellular eukaryotes. However, the ...
Horizontal gene transfer, the acquisition of genes across species boundaries, is a major source of novel phenotypes that enables microbes to rapidly adapt to new environments. How the transferred gene alters the growth - fitness - of the new host affects the success of the horizontal gene transfer event and how rapidly the gene spreads in the population. Several selective barriers - factors that impact the fitness effect of the transferred gene - have been suggested to impede the likelihood of horizontal transmission, however experimental evidence is scarce. The objective of this study was to determine the fitness effects of orthologous genes transferred from Salmonella enterica serovar Typhimurium to Escherichia coli to identify the selective barriers using highly precise experimental measurements. We found that most gene transfers result in strong fitness costs. Previously identified evolutionary barriers - gene function and the number of protein-protein interactions - did not predict the fitness
Phylogenetic reconstructions of bacterial species from DNA sequences are hampered by the existence of horizontal gene transfer. One possible way to overcome the confounding influence of such movement of genes is to identify and remove sequences which are responsible for significant character incongruence when compared to a reference dataset free of horizontal transfer (e.g., multilocus enzyme electrophoresis, restriction fragment length polymorphism, or random amplified polymorphic DNA) using the incongruence length difference (ILD) test of Farris et al. {[}Cladistics 10 (1995) 315]. As obtaining this whole genome dataset prior to the reconstruction of a phylogeny is clearly troublesome, we have tested alternative approaches allowing the release from such reference dataset, designed for a species with modest level of horizontal gene transfer, i.e., Escherichia coli. Eleven different genes available or sequenced in this work were studied in a set of 30 E. coli reference (ECOR) strains. Either ...
Horizontal or lateral gene transfer (HGT or LGT) is the transmission of portions of genomic DNA between organisms through a process decoupled from vertical inheritance. In the presence of HGT events, different fragments of the genome are the result of different evolutionary histories. This can therefore complicate the investigations of evolutionary relatedness of lineages and species. Also, as HGT can bring into genomes radically different genotypes from distant lineages, or even new genes bearing new functions, it is a major source of phenotypic innovation and a mechanism of niche adaptation. For example, of particular relevance to human health is the lateral transfer of antibiotic resistance and pathogenicity determinants, leading to the emergence of pathogenic lineages. Inferring horizontal gene transfer through computational identification of HGT events relies upon the investigation of sequence composition or evolutionary history of genes. Sequence composition-based (parametric) methods ...
As the genomes of many new creatures rapidly fill the public DNA sequence databases, the problems for the grand evolutionary story are becoming overwhelming. One issue is the fact that different creatures have unique sets of genes specific to their kind with no apparent evolutionary history. To explain this glaring problem, evolutionists have resorted to the myth of pervasive horizontal gene transfer.. Horizontal gene transfer (HGT) is the process whereby genes are transferred from one type of creature to another without sexual reproduction. Earlier in my career, I participated in a study (published in the journal Science), in which we found that the pathogenic bacterium Wolbachia had transferred large portions of its DNA into the genomes of both worms and insects.1 The Wolbachia bacterium is able to do this extraordinary feat by targeting the cells of reproductive organs so that the transferred DNA is literally inherited in the host. However, we also observed that very few of these transferred ...
Lateral gene transfer (or horizontal gene transfer), an atypical mechanism of transferring genes between species, has almost become the default explanation for genes that display an unexpected composition or phylogeny. Numerous methods of detecting lateral gene transfer events all rely on two fundamental strategies: primary structure composition or gene tree/species tree comparisons. Discouragingly, the results of these different approaches rarely coincide. With the wealth of genome data now available, detection of laterally transferred genes is increasingly being attempted in large uncurated eukaryotic datasets. However, detection methods depend greatly on the quality of the underlying genomic data, which are typically complex for eukaryotes. Furthermore, given the automated nature of genomic data collection, it is typically impractical to manually verify all protein or gene models, orthology predictions and multiple sequence alignments, requiring researchers to accept a substantial margin of ...
Pathogenicity islands (PAIs), as termed in 1990, are a distinct class of genomic islands acquired by microorganisms through horizontal gene transfer. Pathogenicity islands are found in both animal and plant pathogens. Additionally, PAIs are found in both gram-positive and gram-negative bacteria. They are transferred through horizontal gene transfer events such as transfer by a plasmid, phage, or conjugative transposon. Therefore, PAIs contribute to microorganisms ability to evolve. One species of bacteria may have more than one PAI. For example, Salmonella has at least five. An analogous genomic structure in rhizobia is termed a symbiosis island. Pathogenicity islands (PAIs) are incorporated in the genome, chromosomally or extrachromosomally, of pathogenic organisms, but are usually absent from those nonpathogenic organisms of the same or closely related species. They may be located on a bacterial chromosome or may be transferred within a plasmid or can be found in bacteriophage genomes. The ...
The repABC plasmid family, which is extensively present within Alphaproteobacteria, and some secondary chromosomes of the Rhizobiales have the particular feature that all the elements involved in replication and partitioning reside within one transcriptional unit, the repABC operon. Given the functional interactions among the elements of the repABC operon, and the fact that they all reside in the same operon, a common evolutionary history would be expected if the entire operon had been horizontally transferred. Here, we tested whether there is a common evolutionary history within the repABC operon. We further examined different incompatibility groups in terms of their differentiation and degree of adaptation to their host. We did not find a single evolutionary history within the repABC operon. Each protein had a particular phylogeny, horizontal gene transfer events of the individual genes within the operon were detected, and different functional constraints were found within and between the Rep proteins
To test whether these genes have been acquired from bacteria through horizontal gene transfer, firstly, the distribution of CWDE genes in the whole phylum of Nematoda will be investigated. Secondly, it will be studied whether CWDE sequences are physically clustered in pathogenicity islands. ...
Horizontal gene transfer (HGT) is a fast-track mechanism that allows genetically unrelated organisms to exchange genes for rapid environmental adaptation. We developed a new phyletic distribution-based software, HGT-Finder, which implements a novel bioinformatics algorithm to calculate a horizontal transfer index and a probability value for each query gene. Applying this new tool to the Aspergillus fumigatus, Aspergillus flavus, and Aspergillus nidulans genomes, we found 273, 542, and 715 transferred genes (HTGs), respectively. HTGs have shorter length, higher guanine-cytosine (GC) content, and relaxed selection pressure. Metabolic process and secondary metabolism functions are significantly enriched in HTGs. Gene clustering analysis showed that 61%, 41% and 74% of HTGs in the three genomes form physically linked gene clusters (HTGCs). Overlapping manually curated, secondary metabolite gene clusters (SMGCs) with HTGCs found that 9 of the 33 A. fumigatus SMGCs and 31 of the 65 A. nidulans SMGCs share
Horizontal gene transfer (HGT) in bacteria and archaea occurs through phage transduction, transformation, or conjugation, and the latter is particularly important for the spread of antibiotic resistance. Clustered, regularly interspaced, short palindromic repeat (CRISPR) loci confer sequence-directe …
Determining the photosynthetic relatives of Rafflesiales has long presented a challenge owing to the extreme reduction and/or modification of morphological structures that have accompanied the evolution of this lineage [3, 11]. Molecular phylogenetic approaches, although providing great promise in resolving such questions, also come with their own set of challenges that includes losses of some genes, substitution rate increases in other genes, and horizontal gene transfer. Examples of the first process can be seen in chloroplast genes such as rbcL that are typically used to infer phylogenetic relationships among angiosperms but have not yet been amplified from any Rafflesiales and are presumed lost [5]. Increased substitution rates in the normally conservative plastid rDNA has been demonstrated in these holoparasites [4, 12]. Similarly, accelerated rates in mitochondrial SSU rDNA, typically very conservative in many photosynthetic angiosperms, occur in Rafflesia and Cytinus [13]. Despite these ...
Genomes of living organisms are comprised of very long DNA molecules. A fundamental question is by what mechanisms are specific loci along these genomes found, with high efficiency and at relevant physiological times. We address this question in the case of horizontal gene transfer processes such as viral transduction and conjugation, which result in the rapid acquisition of new traits in bacteria. We use the infection of E. coli cells by bacteriophage lambda, whose DNA integrates at a unique site into the bacterial genome, when following the lysogenic pathway. To shed light on the mechanisms by which lambda DNA finds its unique integration site, we follow in real time individual lambda DNAs and their integration site within live cells using fluorescent markers, until lysogeny is established, revealing the dynamics of the search process.. ...
1997) Horizontal gene transfer and the evolution of resistance and virulence determinants in Streptococcus. JOURNAL OF APPLIED MICROBIOLOGY, 83 (Suppl. S). S42-S51 ...
This is a contribution to the history of scientific advance in the past 70 years concerning the identification of genetic information, its molecular structure, the identification of its functions and the molecular mechanisms of its evolution. Particular attention is thereby given to horizontal gene transfer among microorganisms, as well as to biosafety considerations with regard to beneficial applications of acquired scientific knowledge.
Horizontal Gene Transfer Regulation in Bacteria as a -Spandrel- of DNA Repair Mechanisms. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Acquisition of genes via horizontal transfer rather than by inheritance is frequently observed in bacteria. Now, Swedish researchers demonstrate that a similar phenomenon can occur between eucaryotic cells. Oncogenes from a dying cell can be transferred to a nearby cell via phagocytosis, a process through which one cell engulfs another. If the recipient cell is already genetically unstable, the newly acquired oncogenes can lead to tumor formation.. The researchers propose that this horizontal transfer of genes could be one route by which cells accumulate genetic abnormalities. The study also indicates that even after a cell dies, its genetic material entire chromosomes in some cases can be rescued by other cells.. The scientists mixed dying rat cells carrying cancer-causing oncogenes with mouse cells lacking p53, a tumor-suppressing gene. The p53-deficient cells developed tumor-like characteristics. The same experiment was done with mouse cells carrying p53. In contrast, however, the rat cells ...
Cellular metabolism is the network of chemical reactions that organisms use to convert input molecules into the molecules and energy they need to live and grow. Core metabolic processes and their enzyme catalysts are often conserved among the different kingdoms of life, which has allowed many species metabolic networks to be automatically reconstructed from their genome sequences by the identification of homologs [1-5]. In addition to core metabolic processes, peripheral processes allow species to adapt to different environments - for example, metabolism of a rare sugar. This adaptation can be driven by the gain of genes encoding enzymes through horizontal gene transfer (HGT) [6], and this process has for some time been seen as an important aspect of prokaryotic evolution [7-9]. But as more eukaryotic genome sequences have become available, it has become clear that HGT has also occurred in the evolutionary histories of the eukaryotes [10].. HGT is likely to have had a more important influence ...
As our project suggests the release of genetically modified bacterium into the environment, we feel it is necessary to contain the risk of horizontal gene transfer. Horizontal gene transfer can occur by the release of genetic information through cell lysis, and subsequent transformation of other bacteria. We decided we could target this system by constitutively expressing a nuclease. Any DNA released from the cell would therefore be digested, before it could diffuse, and transform wild-type bacteria. For this system we have selected a extracellular nuclease from Staphylococcus aureus (nucB), which has been well characterized (1-3) however it lacks the signal peptide for secretion to periplasm in E. coli. We chose DsbA (BBa_K243002) signal sequence that enables export of our nuclease to periplasm, thus it will allow us to digest extracellular genetic material. As horizontal gene transfer can also occur via bacteria conjugation, we are proposing a multi-containment system, consisting of three ...
As our project suggests the release of genetically modified bacterium into the environment, we feel it is necessary to contain the risk of horizontal gene transfer. Horizontal gene transfer can occur by the release of genetic information through cell lysis, and subsequent transformation of other bacteria. We decided we could target this system by constitutively expressing a nuclease. Any DNA released from the cell would therefore be digested, before it could diffuse, and transform wild-type bacteria. For this system we have selected a extracellular nuclease from Staphylococcus aureus (nucB), which has been well characterized (1-3) however it lacks the signal peptide for secretion to periplasm in E. coli. We chose DsbA (BBa_K243002) signal sequence that enables export of our nuclease to periplasm, thus it will allow us to digest extracellular genetic material. As horizontal gene transfer can also occur via bacteria conjugation, we are proposing a multi-containment system, consisting of three ...
Genetic material is inherited from parents to offspring and this process is known as vertical transmission. However genetic material can be transferred form one organism to another in a non-genealogical fashion. Such type of transmission is defined as horizontal transmission or gene transfer (HGT) (1). Although mechanisms for the transfer of genetic material between organisms were known from the early years of molecular biology and genetics research, and the theoretical potential of cross-species gene transfer in evolution was proposed in the 1980s, the concept of HGT emerged in the 1990s (2). It was invoked as an alternative explanation for rarely observed incongruent phylogenetic relationships between species (2). However, the recent availability of genome sequence information and the thorough study of multiple pro- and eukaryotic genomes has revealed that HGT is pervasive and powerful among microbes (1,2,3). Additionally, more recent studies have shown that HGT is also evident between animals ...
This quote is deeply troubling. Genome sequencing did not reveal a new mechanism of evolution. And it is thus also inaccurate to say it would not have been discovered any other way. Lateral gene transfer was studies for many many many years before the first genome sequence was determined. Certainly, comparative genome analysis helped reveal the extent of gene transfer but it is seriously inaccurate to say it revealed a new mechanism of evolution. Here for example is a link to a google search for the specific phrase lateral gene transfer in papers published prior to 1995. And here is one for the phrase horizontal gene transfer ...
Bacilladnaviruses have single-stranded (ss) DNA genomes and infect diatoms, a major group of unicellular algae widespread in aquatic habitats. Despite their
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Aims To purify and characterize an antimicrobial proteins (bacteriocin) isolated from your dairy product-derived The cell-free supernatant (CFS) of overnight cultures was active against and also against clinical isolates of and At the same time, several isolates of vaginal probiotic were resistant to the CFS. 3-D image of the molecules structure. It was determined to be a circular molecule of 35 amino acids with a very unique post-translational structure, namely three sulfur cross-links between cysteine and the 2004). Horizontal gene transfer (HGT) is usually a mechanism employed by bacteria as a means of acquiring new genetic properties. Although it was once hard to establish instances of HGT, genetic analysis now provides unmistakable supportive evidence. The evolutionary modification of traits is typically a slow and lengthy process defined by point mutations that inactivate or activate new regions of genes. In comparison, HGT can rapidly switch whole features of a species for generations to ...
1] Christopher M. Thomas & Kaare M. Nielsen. Mechanisms of, and Barriers to, Horizontal Gene Transfer between Bacteria. Nature Reviews Microbiology 3, 711-721 (September 2005) [2] Peter Gogarten & Jeffrey P. Townsend. Horizontal gene transfer, genome innovation and evolution. Nature Reviews Microbiology 3, 679-687 (September 2005) [3] Søren J. Sørensen, Mark Bailey, Lars H. Hansen, Niels Kroer and Stefan Wuertz. Studying plasmid horizontal transfer in situ: a critical review. Nature Reviews Microbiology 3, 700-710 (September 2005) [4] E. K. Weibel I, B. D. Seiffert. Biosafety investigations in an r-DNA production plant. Appl Microbiol Biotechnol (1993) 39:227-234 [5] Claudia Castro, Liliana González, Juan Carlos Rozo, Gloria Puerto, Wellman Ribón. Biosafety evaluation of the DNA extraction protocol for Mycobacterium tuberculosis complex species, as implemented at the Instituto Nacional de Salud, Colombia. Biomédica 2009;29:561-6 [6] Mark J. Espy, James R. Uhl, Lynne M. Sloan, Jon E. ...
Although the two primary forces driving the overall genome evolution of S. thermophilus consist of genome reduction by iterative gene losses in combination with occasional acquisition of beneficial genes through horizontal gene transfer for adaptation to a rich environment (primarily milk) [6,53,58,59], we show in the present article that CRISPR plays a major role in genome evolution following exposure to phages. Indeed, regressive genome evolution by extensive gene loss has been a key driving force shaping the adaptation of S. thermophilus to the rich milk environment, illustrated by the loss of virulence genes widely distributed in most streptococci. Overall, the DGCC7710 genome shares a high degree of synteny with other S. thermophilus genomes, with a few unique genomic islands and hypervariable loci that include the eps operon, the gp operon and CRISPR-Cas systems. Focusing on genome interplay within host-virus dynamics, we propose that the impact of the virus on host genome evolution is ...
RESULTS: Our model predicts that differential gene mobility drives intragenomic variation in investment in cooperative traits. More mobile loci generate stronger among-individual genetic correlations at these loci (higher relatedness) and thereby allow the maintenance of more cooperative traits via kin selection. By analyzing 21 Escherichia genomes, we confirm that genes coding for secreted proteins-the secretome-are very frequently lost and gained and are associated with mobile elements. We show that homologs of the secretome are overrepresented among human gut metagenomics samples, consistent with increased relatedness at secretome loci across multiple species. The biosynthetic cost of secreted proteins is shown to be under intense selective pressure, even more than for highly expressed proteins, consistent with a cost of cooperation driving social dilemmas. Finally, we demonstrate that mobile elements are in conflict with their chromosomal hosts over the chimeric ensembles social strategy, ...
The subject of this chapter is to describe the methodology for assessing the power of phylogenetic HGT detection methods. Detection power is defined in the framework of hypothesis testing. Rates of...
My friend asked what the implications of this might be. I offered a couple of thoughts. First, I said that just as differences in G+C content between genes in a given organism can sometimes be used to detect foreign genes (e.g., embedded phage/virus genes, horizontal gene transfers, etc.), variations in the purine to pyrimidine ratio of gene coding strands might also be a way to detect foreign genes. For example, in an organism like Clostridium botulinum, where the genomes coding regions have an average purine content of 58.5%, finding a gene with purine content below 46% (two standard deviations away from the mean) might be a tipoff that the gene came from a different organism. This is a useful new technique, because genes with high-purine-content coding regions dont always have high A+T content (thus, detection of horizontal gene transfers via purine loading will expose genes that would otherwise be missed on the basis of G+C content). In other words, two genes might have exactly the same ...
My friend asked what the implications of this might be. I offered a couple of thoughts. First, I said that just as differences in G+C content between genes in a given organism can sometimes be used to detect foreign genes (e.g., embedded phage/virus genes, horizontal gene transfers, etc.), variations in the purine to pyrimidine ratio of gene coding strands might also be a way to detect foreign genes. For example, in an organism like Clostridium botulinum, where the genomes coding regions have an average purine content of 58.5%, finding a gene with purine content below 46% (two standard deviations away from the mean) might be a tipoff that the gene came from a different organism. This is a useful new technique, because genes with high-purine-content coding regions dont always have high A+T content (thus, detection of horizontal gene transfers via purine loading will expose genes that would otherwise be missed on the basis of G+C content). In other words, two genes might have exactly the same ...
My friend asked what the implications of this might be. I offered a couple of thoughts. First, I said that just as differences in G+C content between genes in a given organism can sometimes be used to detect foreign genes (e.g., embedded phage/virus genes, horizontal gene transfers, etc.), variations in the purine to pyrimidine ratio of gene coding strands might also be a way to detect foreign genes. For example, in an organism like Clostridium botulinum, where the genomes coding regions have an average purine content of 58.5%, finding a gene with purine content below 46% (two standard deviations away from the mean) might be a tipoff that the gene came from a different organism. This is a useful new technique, because genes with high-purine-content coding regions dont always have high A+T content (thus, detection of horizontal gene transfers via purine loading will expose genes that would otherwise be missed on the basis of G+C content). In other words, two genes might have exactly the same ...
My friend asked what the implications of this might be. I offered a couple of thoughts. First, I said that just as differences in G+C content between genes in a given organism can sometimes be used to detect foreign genes (e.g., embedded phage/virus genes, horizontal gene transfers, etc.), variations in the purine to pyrimidine ratio of gene coding strands might also be a way to detect foreign genes. For example, in an organism like Clostridium botulinum, where the genomes coding regions have an average purine content of 58.5%, finding a gene with purine content below 46% (two standard deviations away from the mean) might be a tipoff that the gene came from a different organism. This is a useful new technique, because genes with high-purine-content coding regions dont always have high A+T content (thus, detection of horizontal gene transfers via purine loading will expose genes that would otherwise be missed on the basis of G+C content). In other words, two genes might have exactly the same ...
November 20, 2016 by Dr Rajiv Desai. Antimicrobial resistance (AMR): ______ ______ Prologue: Within a few days of scraping his leg in a scooter accident in 2009, nine-year-old Brock Wade was in hospital fighting for his life with a methicillin-resistant staphylococcus aureus (MRSA) infection. Once the infection - caused by one of the bacteria most often resistant to antibiotics - has been diagnosed, doctors put him on five different antibiotics. After a month in the hospital, and against all odds, Brock recovered and was well enough to come home. Scenarios such as this case are increasingly being played out all over the world. But not all the thousands of patients that contract drug-resistant bacterial infections every year are as lucky as Brock. And the problem looks set to get worse. While infectious agents are becoming more and more resistant to the medicines that are currently in use, not enough drugs are being developed to combat them. WHO […]. ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Using simulations, scientists report that a mixture of termites and plant competition may be responsible for the strange patterns of earth surrounded by plants in the Namib desert. 2 Comments. ...
Professionals in the genetics field generally support editing the genomes of somatic cells, mirroring public opinion, but diverge from nonexperts when it comes to germline editing.. 1 Comment. ...
This is a list of changes made recently to pages linked from a specified page (or to members of a specified category). Pages on your watchlist are bold. ...
Enterococci often acquire antimicrobial resistance through horizontal gene transfer. Relatedness between enterococci with high level resistance to gentamicin and vancomyc..
Classical biology has also saddled us with the phylogenetic tree, an image the biologist invests with a deep and totally unwarranted significance. The tree is no more than a representational device, but to the biologist it is some God-given truth. Thus, for example, we agonize over how the tree can accommodate horizontal gene transfer events, when it should simply be a matter of when (and to what extent) the evolution course can be usefully represented by a tree diagram. Evolution defines the tree, not the reverse. Tree imagery has locked the biologist into a restricted way of looking at ancestors. It is the tree image, almost certainly, that has caused us to turn Darwins conjecture that all organisms might have descended from a simple primordial form into doctrine: the doctrine of common descent. As we shall discuss below, it is also the tree image that has caused biologists (incorrectly) to take the archaea and the eukaryotes to be sister lineages. Much of the current discussion/debate ...
Classical biology has also saddled us with the phylogenetic tree, an image the biologist invests with a deep and totally unwarranted significance. The tree is no more than a representational device, but to the biologist it is some God-given truth. Thus, for example, we agonize over how the tree can accommodate horizontal gene transfer events, when it should simply be a matter of when (and to what extent) the evolution course can be usefully represented by a tree diagram. Evolution defines the tree, not the reverse. Tree imagery has locked the biologist into a restricted way of looking at ancestors. It is the tree image, almost certainly, that has caused us to turn Darwins conjecture that all organisms might have descended from a simple primordial form into doctrine: the doctrine of common descent. As we shall discuss below, it is also the tree image that has caused biologists (incorrectly) to take the archaea and the eukaryotes to be sister lineages. Much of the current discussion/debate ...
Tardigrades are a neglected phylum of endearing animals, also known as water bears or moss piglets (1). They are members of the superphylum Ecdysozoa (2) and sisters to Onychophora and Arthropoda (3, 4). There are about 800 described species (1), although many more are likely to be as yet undescribed (5). All are small (tardigrades are usually classified in the meiofauna) and are found in sediments and on vegetation from the Antarctic to the Arctic, from mountain ranges to the deep sea, and in marine and fresh water environments. Their dispersal may be associated with the ability of many (but not all) species to enter cryptobiosis, losing almost all body water, and resisting extremes of temperature, pressure, and desiccation (6⇓⇓-9), deep space vacuum (10), and irradiation (11). Interest in tardigrades focuses on their utility as environmental and biogeographic markers, the insight their cryptobiotic mechanisms may yield for biotechnology and medicine, and exploration of their development ...
Despite a large agreement between ribosomal RNA and concatenated protein phylogenies, the phylogenetic tree of the bacterial domain remains uncertain in its deepest nodes. For instance, the position of the hyperthermophilic Aquificales is debated, as their commonly observed position close to Thermotogales may proceed from horizontal gene transfers, long branch attraction or compositional biases, and may not represent vertical descent. Indeed, another view, based on the analysis of rare genomic changes, places Aquificales close to epsilon-Proteobacteria. To get a whole genome view of Aquifex relationships, all trees containing sequences from Aquifex in the HOGENOM database were surveyed. This study revealed that Aquifex is most often found as a neighbour to Thermotogales. Moreover, informational genes, which appeared to be less often transferred to the Aquifex lineage than non-informational genes, most often placed Aquificales close to Thermotogales. To ensure these results did not come from long branch
en] alpha-Amylases are present in all kingdoms of the living world. Despite strong conservation of the tertiary structure, only a few amino acids are conserved in interkingdom comparisons. Animal alpha-amylases are characterized by several typical motifs and biochemical properties. A few cases of such alpha-amylases have been previously reported in some eubacterial species. We screened the bacterial genomes available in the sequence databases for new occurrences of animal-like alpha-amylases. Three novel cases were found, which belong to unrelated bacterial phyla: Chloroflexus aurantiacus, Microbulbifer degradans, and Thermobifida fusca. All the animal-like alpha-amylases in Bacteria probably result from repeated horizontal gene transfer from animals. The M. degradans genome also contains bacterial-type and plant-type alpha-amylases in addition to the animal-type one. Thus, this species exhibits alpha-amylases of animal, plant, and bacterial origins. Moreover, the similarities in the extra ...
Horizontal gene transfer in bdelloid rotifers is ancient, ongoing and more frequent in species from desiccating habitats. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Salmonella enterica bacteria have become increasingly resistant to antimicrobial agents, partly as a result of genes carried on integrons. Clonal expansion and horizontal gene transfer may contribute to the spread of antimicrobial drug-resistance integrons in these organisms. We investigated this resistance and integron carriage among 90 isolates with the ACSSuT phenotype (resistance to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline) in a global collection of S. enterica isolates. Four integrons, dfrA12/orfF/aadA2, dfrA1/aadA1, dfrA7, and arr2/blaOXA30/cmlA5/aadA2, were found in genetically unrelated isolates from 8 countries on 4 continents, which supports a role for horizontal gene transfer in the global dissemination of S. enterica multidrug resistance. Serovar Typhimurium isolates containing identical integrons with the gene cassettes blaPSE1 and aadA2 were found in 4 countries on 3 continents, which supports the role of clonal expansion. This study ...
Hybrid zones and the consequences of hybridization have contributed greatly to our understanding of evolutionary processes. Hybrid zones also provide valuable insight into the dynamics of symbiosis since each subspecies or species brings its unique microbial symbionts, including germline bacteria such as Wolbachia, to the hybrid zone. Here, we investigate a natural hybrid zone of two subspecies of the meadow grasshopper Chorthippus parallelus in the Pyrenees Mountains. We set out to test whether co-infections of B and F Wolbachia in hybrid grasshoppers enabled horizontal transfer of phage WO, similar to the numerous examples of phage WO transfer between A and B Wolbachia co-infections. While we found no evidence for transfer between the divergent co-infections, we discovered horizontal transfer of at least three phage WO haplotypes to the grasshopper genome. Subsequent genome sequencing of uninfected grasshoppers uncovered the first evidence for two discrete Wolbachiasupergroups (B and F) ...
PhD fellowship in Bioinformatics and Bacterial Genomics. Searching for ICEs, Integrative and Conjugative Elements in bacteria: development of a tool for the search and the visualization of ICEs, and impact of these elements in the dissemination of antibiotic resistance genes. Background: Mobile genetic elements play a key role in bacterial genome evolution by enabling gene acquisition through horizontal gene transfer (HGT). Multiplication of bacterial genome sequencing projects provided a remarkable opportunity to explore the pool of bacterial mobile genetic elements (mobilome). This shed the light on elements integrated in the chromosome called Integrative and Conjugative Elements (ICEs). These elements are still poorly known although all the very few ICE searches in genomes suggest their high prevalence in bacteria. ICEs encode their own excision, transfer by conjugation and integration. In addition to the genes involved or controlling their mobility, ICEs carry cargo genes, which can ...
The evolutionary histories of genomes and of individual genes are important for understanding the genetic basis of microbial physiology. Genes that have a different history than the rest of the genome due to lateral genetic transfer may provide insight into the unique abilities of closely related organisms, but also serve to disrupt inference of the history of organisms by common lineage. Inconsistent results in phylogenetic signal among different genes and derived by different methods illustrate the need for approaches that can utilize multiple genes and clarify phylogenetic signal across entire genomes. Phylogenetic inference based on models of nucleotide and amino acid substitutions has become the standard, but higher level markers such as conserved insertions and deletions (indels), may provide clearer results.; Indels appear as gaps in the alignment of sequences, but high levels of alignment errors associated with gaps have generally meant their exclusion from phylogenetic analysis. Efforts ...
Vibrio cholerae in O-group 139 was first isolated in 1992 and by 1993 had been found throughout the Indian subcontinent. This epidemic expansion probably resulted from a single source after a lateral gene transfer (LGT) event that changed the serotype of an epidemic V. cholerae O1 El Tor strain to O139. However, some studies found substantial genetic diversity, perhaps caused by multiple origins. To further explore the relatedness of O139 strains, we analyzed nine sequenced loci from 96 isolates from patients at the Infectious Diseases Hospital, Calcutta, from 1992 to 2000. We found 64 novel alleles distributed among 51 sequence types. LGT events produced three times the number of nucleotide changes compared to mutation. In contrast to the traditional concept of epidemic spread of a homogeneous clone, the establishment of variant alleles generated by LGT during the rapid expansion of a clonal bacterial population may be a paradigm in infections and epidemics ...
The results presented here suggest that HGT can prevent the operation of Mullers ratchet in prokaryotic populations, even if on average HGT introduces more deleterious mutations than it removes. The avoidance of Mullers ratchet via transformation and recombination with eDNA might appear somewhat paradoxical because on average eDNA is expected to carry more deleterious mutations than the DNA in live prokaryotic cells. Indeed, it has been long recognized that sex with dead cells is a dubious proposition (Redfield 1988, 2001; Redfield et al. 1997). However, the modeling results indicate that, even though transformation via eDNA is expected to increase the mean mutation load and hence decrease the average fitness of a population, it nevertheless can stop Mullers ratchet. This appears to be the case because HGT provides for the chance to eliminate deleterious mutations, leading to the continual restoration of the least-loaded class. In other words, HGT prolongs the persistence of the ...
Soil bacteria naturally produce antibiotics as a competitive mechanism, with a concomitant evolution, and exchange by horizontal gene transfer, of a range of antibiotic resistance mechanisms. Surveys of bacterial resistance elements in edaphic systems have originated primarily from human-impacted environments, with relatively little information from remote and pristine environments, where the resistome may comprise the ancestral gene diversity. We used shotgun metagenomics to assess antibiotic resistance gene (ARG) distribution in 17 pristine and remote Antarctic surface soils within the undisturbed Mackay Glacier region. We also interrogated the phylogenetic placement of ARGs compared to environmental ARG sequences and tested for the presence of horizontal gene transfer elements flanking ARGs. In total, 177 naturally occurring ARGs were identified, most of which encoded single or multi-drug efflux pumps. Resistance mechanisms for the inactivation of aminoglycosides, chloramphenicol and β-lactam
Horizontal transfer (HT) of transposable elements (TEs) plays a key role in prokaryotic evolution, and mounting evidence suggests that it has also had an important impact on eukaryotic evolution. Although many prokaryote-to-prokaryote and eukaryote-to-eukaryote HTs of TEs have been characterized, only few cases have been reported between prokaryotes and eukaryotes. Here, we carried out a comprehensive search for all major groups of prokaryotic insertion sequences (ISs) in 430 eukaryote genomes. We uncovered a total of 80 sequences, all deriving from the IS607 family, integrated in the genomes of 14 eukaryote species belonging to four distinct phyla (Amoebozoa, Ascomycetes, Basidiomycetes, and Stramenopiles). Given that eukaryote IS607-like sequences are most closely related to cyanobacterial IS607 and that their phylogeny is incongruent with that of their hosts, we conclude that the presence of IS607-like sequences in eukaryotic genomes is the result of several HT events. Selection analyses further
Strategy for In Situ Detection of Natural Transformation-Based Horizontal Gene Transfer Events - they used a pUC derived plasmid called pCLT that they got from Palmen and Hellingwerf ...
DARPA SBIR 12.2 Topic Descriptions. SB122-001 TITLE: Controlling Antibiotic Resistant or Highly Virulent Pathogens Through Plasmid. Curing. TECHNOLOGY AREAS: Chemical/Bio Defense, Biomedical. OBJECTIVE: Develop a novel plasmid curing therapeutic capable of displacing antibiotic resistance and/or virulence causing plasmids from bacteria. Therapeutic interventions are sought that will be efficacious against a range of human pathogens of interest to the DoD.. DESCRIPTION: The combined threat of the increasing prevalence of drug-resistant bacteria and a diminishing antibiotic pipeline places our warfighters at risk not only from health care associated and community acquired infections, but also from pandemics, emerging infectious pathogens and the intentional use of resistant pathogens for bioterrorism. One of the major routes by which bacterial pathogens become resistant to antibiotics and more virulent is through Horizontal Gene Transfer (HGT), which allows for genetic material transfer in the ...
Bacterial toxin-antitoxin (TA) systems are diverse and widespread in the prokaryotic kingdom. They are composed of closely linked genes encoding a stable toxin that can harm the host cell and its cognate labile antitoxin, which protects the host from the toxins deleterious effect. TA systems are thought to invade bacterial genomes through horizontal gene transfer. Some TA systems might behave as selfish elements and favour their own maintenance at the expense of their host. As a consequence, they may contribute to the maintenance of plasmids or genomic islands, such as super-integrons, by post-segregational killing of the cell that loses these genes and so suffers the stable toxins destructive effect. The function of the chromosomally encoded TA systems is less clear and still open to debate. This Review discusses current hypotheses regarding the biological roles of these evolutionarily successful small operons. We consider the various selective forces that could drive the maintenance of TA systems in
We recently demonstrated that the Escherichia coli ribosome is robust enough to accommodate foreign 16S rRNAs from diverse gamma- and beta-proteobacteria bacteria (Kitahara, Yasutake, and Miyazaki. Proc Natl Acad Sci U S A. 109:19220-19225, 2012, doi: 10.1073/pnas.1213609109). Therein, we used the common universal primers Bac8f and UN1541r to obtain a nearly full-length gene. However, we noticed that these primers overlap variable sites at 19[A/C] and 1527[U/C] in Bac8f and UN1541r, respectively, and thus the amplicon could contain mutations. This is problematic, particularly for the former site, because the 19th nucleotide pairs with the 916th nucleotide, which is a part of the
Bacteria are programmed using synthetic biology to release gas to report when they exchange DNA through horizontal gene transfer, the process by which organisms share genetic traits without a parent-to-child relationship.
In eukaryotic organisms, horizontal gene transfer (HGT) is regarded as an important though infrequent source of reticulate evolution. Many confirmed instances of natural HGT involving multicellular eukaryotes come from flowering plants. This review intends to provide a synthesis of present knowledge regarding HGT in higher plants, with an emphasis on tobacco and other species in the Solanaceae family because there are numerous detailed reports concerning natural HGT events, involving various donors, in this family. Moreover, in-depth experimental studies using transgenic tobacco are of great importance for understanding this process. Valuable insights are offered concerning the mechanisms of HGT, the adaptive role and regulation of natural transgenes, and new routes for gene trafficking. With an increasing amount of data on HGT, a synthetic view is beginning to emerge.. ...
Although there is tremendous interest in understanding the evolutionary roles of horizontal gene transfer (HGT) processes that occur during chronic polyclonal infections, to date there have been few studies that directly address this topic. We have characterized multiple HGT events that most likely occurred during polyclonal infection among nasopharyngeal strains of Streptococcus pneumoniae recovered from a child suffering from chronic upper respiratory and middle-ear infections. Whole genome sequencing and comparative genomics were performed on six isolates collected during symptomatic episodes over a period of seven months. From these comparisons we determined that five of the isolates were genetically highly similar and likely represented a dominant lineage. We analyzed all genic and allelic differences among all six isolates and found that all differences tended to occur within contiguous genomic blocks, suggestive of strain evolution by homologous recombination. From these analyses we identified
We have found that cell-cell signaling is used to regulate horizontal transfer of the integrative and conjugative element ICEBs1, a conjugative transposon found in the B. subtilis genome. These types of elements are widespread in the microbial world and contribute to horizontal gene transfer, evolution, virulence, and the spread of antibiotic resistance. ICEBs1 is regulated by population density and cell-cell signaling in two ways. 1) At high population density, in the presence of potential mating partners, the element is stimulated to excise from the chromosome and can then transfer to potential recipients. 2) However, if the potential recipients already contain a copy of the element, then excision of the element is inhibited and there is little or no transfer to the potential recipients that already contain the element. We found that the secreted pentapeptide, a product of phrI, that regulates this recognition of self is encoded in the element. In the absence of this peptide, as cells grow ...
Archaeal and bacterial genomes contain a number of genes of foreign origin that arose from recent horizontal gene transfer, but the role of integrative elements (IEs), such as viruses, plasmids, and transposable elements, in this process has not been extensively quantified. Moreover, it is not known whether IEs play an important role in the origin of ORFans (open reading frames without matches in current sequence databases), whose proportion remains stable despite the growing number of complete sequenced genomes. We have performed a large-scale survey of potential recently acquired IEs in 119 archaeal and bacterial genomes. We developed an accurate in silico Markov model-based strategy to identify clusters of genes that show atypical sequence composition (clusters of atypical genes or CAGs) and are thus likely to be recently integrated foreign elements, including IEs. Our method identified a high number of new CAGs. Probabilistic analysis of gene content indicates that 56% of these new CAGs are likely
Typically, the proto-language is not known directly. It is by definition a linguistic reconstruction formulated by applying the comparative method to a group of languages featuring similar characteristics.[2] The tree is a statement of similarity and a hypothesis that the similarity results from descent from a common language. The comparative method, a process of deduction, begins from a set of characteristics, or characters, found in the attested languages. If the entire set can be accounted for by descent from the proto-language, which must contain the proto-forms of them all, the tree, or phylogeny, is regarded as a complete explanation and by Occams razor, is given credibility. More recently such a tree has been termed perfect and the characters labelled compatible. No trees but the smallest branches are ever found to be perfect, in part because languages also evolve through horizontal transfer with their neighbours. Typically, credibility is given to the hypotheses of highest ...
Recent analyses of bacterial genomes have shown that integrated elements that transfer by conjugation play an essential role in horizontal gene transfer. Among these elements, the integrative and mobilizable elements (IMEs) are known to encode their own excision and integration machinery, and to carry all the sequences or genes necessary to hijack the mating pore of a conjugative element for their own transfer. However, knowledge of their prevalence and diversity is still severely lacking. In this work, an extensive analysis of 124 genomes from 27 species of Streptococcus reveals 144 IMEs. These IMEs encode either tyrosine or serine integrases. The identification of IME boundaries shows that 141 are specifically integrated in 17 target sites. The IME-encoded relaxases belong to nine superfamilies, among which four are previously unknown in any mobilizable or conjugative element. A total of 118 IMEs are found to encode a non-canonical relaxase related to rolling circle replication initiators (belonging
RESEARCH INTERESTS Dr. Pascal Simonet obtained his PhD in 1983. Currently his research group investigates the evolution potential of bacteria in environments such as the soil and plants. For more than 15 years the research group entitled « Gene Transfer and Bacterial Adaptation » that he led at the University of Lyon has had the general objectives of determining the involvement of horizontal gene transfers (HGT) in the adaptation and evolution of bacteria to new environments. Studies of the group focused mainly on natural genetic transformation and also, but at a lesser extent, on conjugation. These objectives lead the group to develop soil DNA extraction methods and it was among the first to investigate environmental bacteria with metagenomic approaches. Several of the studies were devoted to investigate the fate of DNA released by genetically engineered organisms including the possibility that recombinant DNA, and particularly antibiotic resistance genes transforms indigenous bacteria. The ...
The question of whether bacterial species objectively exist has long divided microbiologists. A major source of contention stems from the fact that bacteria regularly engage in horizontal gene transfer (HGT), making it difficult to ascertain relatedness and draw boundaries between taxa. A natural way to define taxa is based on exclusivity of relatedness, which applies when members of a taxon are more closely related to each other than they are to any outsider. It is largely unknown whether exclusive bacterial taxa exist when averaging over the genome or are rare due to rampant hybridization. Here, we analyze a collection of 701 genomes representing a wide variety of environmental isolates from the family Streptomycetaceae, whose members are competent at HGT. We find that the presence/absence of auxiliary genes in the pan-genome displays a hierarchical (tree-like) structure that correlates significantly with the genealogy of the core-genome. Moreover, we identified the existence of many exclusive taxa,
The second assumption is that bacteria can easily take up DNA from the environment. In the case of Vibrio cholerae that is true, if theyre growing on a crab shell (freely available article). I think LabRat is highlighting the importance and sexiness of Horizontal Gene Transfer (HGT). HGT clearly occurs between bacteria, not just different cells of the same species, but also different species, hell even different phyla! It is a phenomenon built of WIN! and really HGT was a game changer for how we (scientists) think about biology. HGT is important and its discovery revolutionized bacterial genetics. But lets not overstate it. HGT has occurred and is important. But is it a potential force of evolution? Yes. Is it the driving force? No, well at least not necessarily. In fact, bacterial species have a way to generate genetic diversity without taking up DNA from the environment, which is based on DNA polymerase IV. DNA polymerase IV is an error prone DNA polymerase, which means when replicating the ...
The study of genetic exchange resulting from natural hybridization, horizontal gene transfer, and viral recombination has long been marked by controversy between researchers holding different conceptual frameworks. Those subscribing to a doctrine of species purity have traditionally been reluctant to recognise inferences suggesting anything other than a marginal role for non-allopatric divergence leading to gene transfer between different lineages.
Horizontal gene transfer (HGT) is a real thing. Its a process through which bacteria sometimes take up DNA from the environment and integrate it into their own genomes. Animals cant do HGT, but rather infamously, a paper was published in December 2015 that made the bold claim that tardigrades had a unique ability to absorb all kinds of DNA. That paper was instantly controversial in the scientific community, and not surprisingly its findings were being disputed in the Twittersphere within days of its appearance. Surprisingly, the same journal (PNAS) that published the bogus HGT claim published a second paper just a few months later showing that tardigrades do not absorb foreign DNA into their genome. That plus a third paper showed that the original paper had mistakenly identified contaminating DNA as part of the tardigrades own genome. This rapid correction of the record was a win for science; Ive used this example to demonstrate to my undergraduate class how sloppy science (the first paper) ...
Horizontal gene transfer (HGT) is a real thing. Its a process through which bacteria sometimes take up DNA from the environment and integrate it into their own genomes. Animals cant do HGT, but rather infamously, a paper was published in December 2015 that made the bold claim that tardigrades had a unique ability to absorb all kinds of DNA. That paper was instantly controversial in the scientific community, and not surprisingly its findings were being disputed in the Twittersphere within days of its appearance. Surprisingly, the same journal (PNAS) that published the bogus HGT claim published a second paper just a few months later showing that tardigrades do not absorb foreign DNA into their genome. That plus a third paper showed that the original paper had mistakenly identified contaminating DNA as part of the tardigrades own genome. This rapid correction of the record was a win for science; Ive used this example to demonstrate to my undergraduate class how sloppy science (the first paper) ...
Plasmid-mediated horizontal gene transfer is recognized as a major driving force for bacterial adaptation and diversification. Different environmental settings have distinct bacterial community compositions, which determine-possibly with the exception of broad host range plasmids-the type of dominant plasmids that can be found. It is assumed that only a fraction of a population carries plasmids, which ensures a rapid adaptation of the population to changing environmental conditions ( 1 ). Without a doubt, plasmid-mediated spread of antibiotic resistance genes among bacteria of different taxa is one of the most impressive examples of bacterial plasticity in response to various selective pressures ( 2 , 3 ). While the molecular biology of the plasmid-encoded replication, maintenance, and transfer processes of some plasmids has been studied for decades, little attention has been paid to their dissemination in the environment, their ecology, and the factors that drive their spread and diversification. In
Comparison of complete genomes of Bacteria and Archaea shows that gene content varies considerably and that genomes evolve quite rapidly via gene duplication and deletion and horizontal gene transfer. We analyze a diverse set of 92 Bacteria and 79 Archaea in order to investigate the processes governing the origin and evolution of families of related genes within genomes. Genes were clustered into related groups using similarity criteria derived from BLAST. Most clusters contained genes from only one or a small number of genomes, and relatively few core clusters were found that spanned all genomes. Gene clusters found in larger numbers of genomes tended to have larger numbers of genes per genome; however, clusters with unusually large numbers of genes per genome were found among both narrowly and widely distributed clusters. Larger genomes were found to have larger mean gene family sizes and a greater proportion of families of very large size. We used a model of birth, death, and innovation to predict
I dunno.. Symbiogenetic cell fusions, horizontal DNA transfer, mutagenic DNA repair, reverse transcription of RNA into DNA, mobile genetic elements, interspecific hybridization and whole genome doubling, which Shapiro says he discusses in his book, could-taken together-explain a lot of things that are currently at the mercy of Darwins duds. (See this, for example.). The only way we could find out what mechanisms account for which changes would be to defund Darwinism, and throw the whole thing open for serious research (as opposed to current research that attempts to demonstrate Darwin at work and portrays the rapidly growing number of failures as some kind of a big surprise).. Yuh. Surprise, surprise.. But good luck defunding Darwinism when those who oppose it undercut each other. And rhetoric about the ideals of liberty, democracy and opportunity on which this nation was founded sounds rather thin after Amarillo.. So now, what is really at issue here? Shapiro claims to have abundant ...
Antibiotic resistance prompted with the overuse of antimicrobial agents may arise from a number of mechanisms particularly horizontal gene transfer of virulence and antibiotic resistance genes which is definitely often facilitated by biofilm formation. in level of resistance and virulence not merely in the framework from the biofilm but GDC-0941 also as inextricably linked pathologies. Observationally it really is very clear that improved virulence as well as the arrival of antibiotic level of resistance often arise nearly simultaneously; nevertheless their genetic connection GDC-0941 has been relatively ignored. Although the complexities of genetic regulation in a multispecies community may obscure a causative relationship uncovering key genetic interactions between virulence and resistance in biofilm bacteria is essential to identifying new druggable targets ultimately providing a drug discovery and development pathway to improve treatment options for chronic and recurring infection. spp. are ...
Bioinformatics, the use of computer resources to understand biological information, is an important tool in research, and can be easily integrated into the curriculum of undergraduate courses. Such an example is provided in this series of four activities that introduces students to the field of bioinformatics as they design PCR based tests for pathogenic E. coli strains. A variety of computer tools are used including BLAST searches at NCBI, bacterial genome searches at the Integrated Microbial Genomes (IMG) database, protein analysis at Pfam and literature research at PubMed. In the process, students also learn about virulence factors, enzyme function and horizontal gene transfer. Some or all of the four activities can be incorporated into microbiology or general biology courses taken by students at a variety of levels, ranging from high school through college. The activities build on one another as they teach and reinforce knowledge and skills, promote critical thinking, and provide for student ...
Our laboratory uses molecular biological and computational methods to study the genes and genomes of prokaryotic and eukaryotic (nucleus-containing) microorganisms. Using a comparative genomics approach, we are interested in (1) the pivotal molecular and biochemical events that have shaped the evolution of eukaryotes; (2) understanding the evolutionary relationships amongst eukaryotic microbes; (3) how endosymbionts become organelles; and (4) understanding how eukaryotic genes, genomes and proteins change over time. We currently study the spread of photosynthetic organelles (chloroplasts) in eukaryotes and the extent to which lateral (horizontal) gene transfer has impacted the gene content of nuclear genomes.. ...
Classification seeks to describe the diversity of bacterial species by naming and grouping organisms based on similarities. Bacteria can be classified on the basis of cell structure, cellular metabolism or on differences in cell components, such as DNA, fatty acids, pigments, antigens and quinones.[101] While these schemes allowed the identification and classification of bacterial strains, it was unclear whether these differences represented variation between distinct species or between strains of the same species. This uncertainty was due to the lack of distinctive structures in most bacteria, as well as lateral gene transfer between unrelated species.[148] Due to lateral gene transfer, some closely related bacteria can have very different morphologies and metabolisms. To overcome this uncertainty, modern bacterial classification emphasises molecular systematics, using genetic techniques such as guanine cytosine ratio determination, genome-genome hybridisation, as well as sequencing genes that ...
To help battle genetic diseases, scientists at USF are turning to the sea and a certain kind of slug that could unlock the secret to curing many human ailments.. Seventy-five to 80 percent of all human diseases are genetic. One way to cure these is gene replacement therapy - the insertion of healthy genes into cells - but this is biochemically and physiologically difficult, said Dr. Sidney Pierce, a professor and chair of the biology department. Consequently, biologists worldwide have been looking for gene transfers in nature. The process occurs in retroviruses like HIV and in bacteria and various microorganisms, but between two multi-cellular organisms it has been difficult to prove. Until now.. Pierce, who has done research on slugs for about ten years, along with Steve Massey, a post-doctoral student, and Nick Curtis, a biology graduate student, discovered a case of horizontal gene transfer between two different species found off the coast of Marthas Vineyard, in the waters around the Keys ...
Bacteria are slippery little suckers. They evolve rapidly, developing resistance to antibiotics and therefore becoming increasingly difficult to deal with. Now, for the first time, researchers have caught on film one of the mechanisms the microbes use for this speedy evolution.. Two Vibrio cholerae bacteria - the pathogen responsible for cholera - sit under a microscope, glowing a vivid green. As we watch, a tendril snakes forth from one of the bacterium, harpooning a piece of DNA and carrying it back to its body.. That appendage is called a pili, and the process whereby the bacteria incorporates the new genetic material from a different organism into its own DNA to expedite its evolution is called horizontal gene transfer.. ...
Transduction (closely linked genes will cotransduce at a higher frequency) C. Recombinant DNA technology 1. cloning of specific DNA fragments on plasmids and the transfer into bacteria via transformation and/or conjugation (Fig. & M.Sc. Genetic mapping of genes on the bacterial chromosome 1. Bacterial transformation is a process of horizontal gene transfer by which some bacteria take up foreign genetic material (naked DNA) from the environment. This method generally gives 104-106 transformants/mg of closed circle plasmid DNA. Identify the chemical meanses of sterilization and disinfection, and their effect on bacterial … ADVERTISEMENTS: In this article we will discuss about:- 1. Prewarm and dry five LB+Kan plates by placing … View Ch 17 - Bacterial & Viral Genetics - Notes Layout.pdf from BIO 101 at Albany College of Pharmacy and Health Sciences. Chapter 17 Bacterial and Viral Genetics 1 1 CDC/Janice Haney. CLICK HERE. Process of Transformation 3. Linkage and Gene Mapping. Biology is brought ...
Hi all, I was wondering if any has hear of a higher eukaryotic gene organization such as this : 2 genes, intronless, facing towards eachother (promotion-wise) that are absolutly critical for the function of a system. these genes show no homology to eachother (or anyother genes for that matter) but are conserved for over 500 million years of evolution. they are absolutly critical for function. these are the recombinase activating genes. they are essential for immune system function-t and b cell rearrangement. a possible theory is that they are the resylt of horizontal gene transfer from a viral infection (intronless, 2 genes for one function right next to each other on the same chromasome...ect) 500 million years ago or so. they are almost completly conserved over this time. question: can anyone support the viral introduction theory? can anyone give me an example of any other system where 2 genes like this are essential for function, may have similar function (well maybe not similar but ...
There is a large literature on gene silencing, in which the transgenes remain in the genome, but are not expressed. More serious, from the safety point of view, is structural instability, the tendency for the transgenic DNA to come loose, to rearrange or become lost in part or in whole in successive generations [2,3]. This could change the transgenic line in unpredictable ways in terms of health and environmental risks. And it will increase the chance of transgenic DNA being taken up by unrelated species to make new combinations with their genetic material. Thats referred to as horizontal gene transfer and recombination. Transgenic DNA can spread to every species that interact with the transgenic plant, in the soil, in the air, in the mouth and gut and the respiratory tracts of animals including human beings ...
Lateral gene transfer may be more common than previously thought. Scientists at U Rochester recently found a pickles entire genome tucked inside its hosts DNA. Such large-scale heritable gene transfers may allow species to acquire new genes and flavors extremely quickly, says Jack Werren, a principle investigator of the study. If such genes provide new abilities in species that cause or transmit deliciousness, they could provide new techniques to deli sandwich-makers. Imagine if the pickle flavor was present in the meat, he says. Think about it.. This study establishes the widespread occurrence and high frequency of a process that we would have dismissed as science fiction until just a few years ago, says W. Ford Doolittle, Canada Research Chair in Comparative Microbial Genomics at Dalhousie University, who is not connected to the study. This is stunning evidence for that old parable: you are what you eat.. Gusss may be the most prolific pickle in the world-a pandemic, as Werren ...
by Roberto | In his recent murder mystery post Dial V for Murder, Christoph stated that fewer that 30 out of STCs 1,200+ posts had dealt with the topic of horizontal gene transfer. Considering the cardinal role of that process in the evolutionary history of microbes, such a small fraction of posts - relative to the importance of the subject matter - led him to argue that one more post on the topic would not prove redundant.
Date: Mon, 15 Mar 2010 11:58:06 -0400 Subject: lambda lunch update: SEMINAR TODAY Lambda Lunch update, 3/15/10: 3/15/10, 3:00 PM, Bldg 10/Lipsett Auditorium: Luciano Marraffini (Stadtman finalist candidate, Northwestern Univ) Self vs. non-self discrimination during CRISPR immunity against horizontal gene transfer 3/18/10*: Kiyoshi Mizuuchi How do bacteria find the middle of a cell? A case study of ATP-driven dynamic bio-patterning two-protein systems 3/25/10*: Ferric Fang Antimicrobial Actions of Nitric Oxide (Laurie Waters) 4/1/10*: Nick Bergman (National Biodefense Analysis and Coutnermeasures Center (NBACC)) Structure and complexity of the bacterial transcriptome (Maureen Kiley) 4/6/10, 11:30 AM, 37/2nd floor conf. room: Chuck Turnbough (U. Ala.) Structure and function of the Bacillus anthracis exosporium (Bob Weisberg) 4/8/10*: Wayne Outten (U of SC) Cross-talk between iron metabolism and biofilm formation in E. coli (Gigi Storz) 4/15/10*: Joerg Vogel (Susan Gottesman) 4/21/10: ...
In article ,Co2Isu.n4r at gpu.utcc.utoronto.ca, lamoran at gpu.utcc.utoronto.ca(L.A. Moran) writes: ,I dont think that either the glutamine synthetase or the HSP70 data offer ,any support for horizontal gene transfer. Maybe it is the EF-Tu and the ,ATPase genes that were transferred from eukaryotes to archaebacteria? (- : I think it is premature to decide what is the transferred portion, and which is the receiving portion. It might be that they turn out to be nearly the same size. I do not think that the elongation factors and ATPases represent a small (!) transferred portion. The grouping of the archaebacteria as separate from the eubacteria is also supported by ribosomes and RNA polymerases (plus cell wall and membrane composition, ..). It has been argued that the functioning of transcription and translation is so essential to the organism that the translation and transcription machineries could not be transferred into another organism that uses different recognition signals in their genes; ...
José Prieto is the author of this article in the Journal of Visualized Experiments: Methodology for the Study of Horizontal Gene Transfer in Staphylococcus aureus
Medical / Nursing / Devices, Lateral Transfer / Boards, Roller | ALPHA PROPS | Medical / Nursing / Devices, Lateral Transfer / Boards, Roller movie props and set dressing available at Alpha Medical Resources
KEYWORDS = {explicit network, from rooted trees, from species tree, lateral gene transfer, phylogenetic network, phylogeny, Program LatTrans, Program PhyloNet ...
See also: horizontal gene transfer. The ability of Agrobacterium to transfer genes to plants and fungi is used in biotechnology ... Agrobacterium is a genus of Gram-negative bacteria established by H. J. Conn that uses horizontal gene transfer to cause tumors ... Marc Van Montagu and Jozef Schell at the University of Ghent (Belgium) discovered the gene transfer mechanism between ... It also carries genes for the biosynthesis of the plant hormones, auxin and cytokinins, and for the biosynthesis of opines, ...
Main article: Horizontal gene transfer. Viruses are an important natural means of transferring genes between different species ... In evolution, viruses are an important means of horizontal gene transfer, which increases genetic diversity.[7] Viruses are ... a b Canchaya C, Fournous G, Chibani-Chennoufi S, Dillmann ML, Brüssow H. Phage as agents of lateral gene transfer. Current ... One of the most effective is the presence of so-called resistance (R) genes. Each R gene confers resistance to a particular ...
... and this horizontal gene transfer is one reason why they served as a major research tool in the early development of molecular ... This approach of using viruses as gene vectors is being pursued in the gene therapy of genetic diseases. An obvious problem to ... Current Gene Therapy. 3: 495-499.. *^ Kolata, Gina (2005-10-06). "Experts Unlock Clues to Spread of 1918 Flu Virus". The New ... Richard Roberts and Phillip Sharp independently showed that the genes of adenovirus contain introns and therefore require gene ...
Oklahoma State - Horizontal Gene Transfer *^ Peter Gogarten. "Horizontal Gene Transfer - A New Paradigm for Biology". esalenctr ... Horizontal gene transfer[edit]. Main article: Horizontal gene transfer. The ancestry of living organisms has traditionally been ... Most likely, these genes were acquired through horizontal gene transfer from viral hosts.[29] ... Horizontal gene transfer makes it more difficult to study the last universal ancestor.[37] However, the universal use of the ...
Inferring horizontal gene transfer. M. *Multi-state modeling of biomolecules. T. *Wikipedia:Ten Simple Rules for Editing ...
CS1 maint: Uses editors parameter (link) Sapp, Jan (2012). "Horizontal Gene Transfer and the Tree of Life". In Joseph Seckbach ... and emphasize the fundamental importance of symbiosis and horizontal gene transfer in heredity and evolution. Sapp was born in ... Sapp, Jan (1987). Beyond the Gene: Cytoplasmic Inheritance and the Struggle for Authority in Genetics. Monographs on the ...
McNeilly, Celia L.; McMillan, David J. (2014-01-01). "Horizontal gene transfer and recombination in Streptococcus dysgalactiae ... However, evidence of horizontal genetic transfer has also been reported. The first pivotal step in infectious pathogenesis is ... "Superantigen-like gene(s) in human pathogenic Streptococcus dysgalactiae, subsp equisimilis: genomic localisation of the gene ... The emm-gene encodes the M-protein, a major virulence factor in both S.pyogenes and Streptococcus dysgalactiae. It is ...
... s are thought to extensively contribute to horizontal gene transfer in natural environments, principally via ... Bacteriophages Promote Horizontal Gene Transfer by Transformation". MBio. 8 (1): e02115-16. doi:10.1128/mBio.02115-16. ISSN ... Their genomes may encode as few as four genes and as many as hundreds of genes. Phages replicate within the bacterium following ... However, some DNA phages such as T4 may have large genomes with hundreds of genes; the size and shape of the capsid varies ...
Horizontal gene transfer speeds the process of genetic transfer since there is no need to wait an entire generation time for ... It is thought that MSSA acquired the resistance gene through the horizontal gene transfer, a method in which genetic ... PMID 24962815.CS1 maint: multiple names: authors list (link) Krishnapillai V (1996). "Horizontal gene transfer". Journal of ... It is theorized that when this S. aureus strain that had acquired the mecA gene was introduced into hospitals, it came into ...
Fournier, G (2009). "Horizontal gene transfer and the evolution of methanogenic pathways". Horizontal Gene Transfer. Methods in ... Another possibility is that evolution of the system involved a horizontal gene transfer between unrelated microorganisms. The ... This requires only the presence of the pylT gene, which encodes an unusual transfer RNA (tRNA) with a CUA anticodon, and the ... In this way a net CH+ 3 is transferred to the cofactor's cobalt atom with a change of oxidation state from I to III. The ...
Syvanen, Michael; Kado, Clarence I. (2002). Horizontal Gene Transfer. Academic Press. p. 405. ISBN 978-0-12-680126-2. Roberts, ... gene duplication, lateral gene transfer, and transposable elements (jumping genes). The neutral theory of molecular evolution, ... ISBN 978-0-632-04708-6 Serres, M. H.; Kerr, A. R.; McCormack, T. J.; Riley, M. (2009). "Evolution by leaps: gene duplication in ... In modern epigenetics, biologists observe that phenotypes depend on heritable changes to gene expression that do not involve ...
Genome-wide experimental determination of barriers to horizontal gene transfer. Science. 2007 318(5855):1449-52. Noonan JP et ... His work on evolutionarily conserved noncoding regions helped highlight the utility of genome comparisons to decode gene ... Metagenomic discovery of biomass-degrading genes and genomes from cow rumen. Science. 2011 28;331(6016):463-7. Rubin EM. ... harnessing sequence comparisons between species for the discovery of genes and non-coding sequences of pivotal evolutionary and ...
This is theoretically possible under principles of "horizontal gene transfer." A heterarchy may be parallel to a hierarchy, ... "horizontal" position of power and authority, each playing a theoretically equal role. But in biological taxonomy, the requisite ... heterarchy can be defined as an organizational form somewhere between hierarchy and network that provides horizontal links that ...
Genetic exchange and recombination still occur, but this is a form of horizontal gene transfer and is not a replicative process ... The transfer of bacterial DNA is under the control of the bacteriophage's genes rather than bacterial genes. Conjugation in the ... Prokaryotes are asexual, reproducing without fusion of gametes, although horizontal gene transfer also takes place. Molecular ... Brown JR (February 2003). "Ancient horizontal gene transfer". Nature Reviews. Genetics. 4 (2): 121-32. doi:10.1038/nrg1000. ...
Nosenko T, Bhattacharya D. Horizontal gene transfer in chromalveolates. BMC Evol Biol. 2007 ... Gene-cluster analysis in chloroplast genomics. Trends Genet. 1999. *Durnford DG, Deane JA, Tan S, McFadden GI, Gantt E, et al. ... Gene trees in species trees. Syst Biol. 1997. *Stiller JW. Plastid endosymbiosis, genome evolution and the origin of green ... Gene. 2008. *Martin W, Rujan T, Richly E, Hansen A, Cornelsen S, et al. Evolutionary analysis of Arabidopsis, cyanobacterial, ...
Kapitola Horizontal Gene Transfer Mediated by Plasmids.. *↑ Graham D. E., Overbeek R, Olsen GJ, Woese CR. An archaeal genomic ... Updated clusters of orthologous genes for Archaea: a complex ancestor of the Archaea and the byways of horizontal gene transfer ... Evidence for lateral gene transfer between Archaea and bacteria from genome sequence of Thermotoga maritima. Nature. 1999, roč ... Integrative modeling of gene and genome evolution roots the archaeal tree of life. S. E4602-E4611. Proceedings of the National ...
Young, JM (2001). "Implications of alternative classifications and horizontal gene transfer for bacterial taxonomy". Int. J. ... Analysis of their 16S rRNA gene sequences suggests that they are a deeply branching lineage that does not belong to the main ... Hansmann, S; Martin W (2000). "Phylogeny of 33 ribosomal and six other proteins encoded in an ancient gene cluster that is ... Achenbach-Richter, L; Woese CR (1988). "The ribosomal gene spacer region in archaebacteria". Syst. Appl. Microbiol. 10: 211-214 ...
Horizontal Gene Transfer and the Evolution of Microvirid Coliphage Genomes. Journal of Bacteriology, 118(3) p1134-1142 ... Gene E is encoded with gene D with a +1 frameshift. Gene K overlaps genes A, B, and C. The origin of replication lies within a ... It encodes 11 genes (in order: A, A*, B, C, K, D, E, J, F, G, and H), nine of which are essential. The nonessential genes are E ... evidence from overlaid genes" J Mol Evol 13(3) 245-252 Fiddes JC, Godson GN (1979) Evolution of the three overlapping gene ...
Bock, R. (2010). "The give-and-take of DNA: horizontal gene transfer in plants". Trends in Plant Science. 15 (1): 11-22. doi: ... Gene transfer in nature and traditional agriculture[edit]. DNA transfers naturally between organisms.[28] Several natural ... It contained three bacterial genes, two CP4 EPSPS genes, and a gene encoding beta-glucuronidase (GUS) from Escherichia coli as ... This CP4 EPSPS gene was cloned and transfected into soybeans.. The plasmid used to move the gene into soybeans was PV-GMGTO4. ...
... gene duplications and occasional horizontal gene transfers. In principle, this process can be summarized in a phylogenetic tree ... This last instance is probably a case of horizontal gene transfer.) Hfq is pleiotropic with a variety of interactions, ... A series of gene duplications of a single eukaryote LSm gene resulted in most (if not all) of the known eukaryote LSm genes. ... pre-transfer RNA, and pre-RNase P. Then, according to this hypothesis, the seven ancestral eukaryote LSm genes duplicated again ...
Bock, R. (2010). "The give-and-take of DNA: horizontal gene transfer in plants". Trends in Plant Science. 15 (1): 11-22. doi: ... It contained three bacterial genes, two CP4 EPSPS genes, and a gene encoding beta-glucuronidase (GUS) from Escherichia coli as ... This CP4 EPSPS gene was cloned and transfected into soybeans. The plasmid used to move the gene into soybeans was PV-GMGTO4. ... Agrobacteria are natural plant parasites.[51] Their natural ability to transfer genes provides another engineering method. To ...
Asexual reproduction, horizontal gene transfer. Asexual reproduction, horizontal gene transfer. Sexual and asexual reproduction ... and the presence of archaea-like genes in certain bacteria, such as Thermotoga maritima, from horizontal gene transfer.[75] The ... Archaea show high levels of horizontal gene transfer between lineages. Some researchers suggest that individuals can be grouped ... "Horizontal Gene Transfer Mediated by Plasmids". Plasmids: Current Research and Future Trends. Caister Academic Press. ISBN 978- ...
Horizontal gene transfer Langille, MG; Hsiao, WW; Brinkman, FS (May 2010). "Detecting genomic islands using bioinformatics ... tools of bacterial horizontal gene transfer and evolution". FEMS Microbiology Reviews. 33 (2): 376-393. doi:10.1111/j.1574- ... The same GI can occur in distantly related species as a result of various types of lateral gene transfer (transformation, ... sometimes due to highly expressed genes) and that horizontally transferred DNA will ameliorate (change to the host genome) over ...
ISBN 978-1-4200-3267-3.CS1 maint: extra text: authors list (link) Francino, edited by M. Pilar (2012). Horizontal gene transfer ... "Arthrobacter aurescens TC1 Atrazine Catabolism Genes trzN, atzB, and atzC Are Linked on a 160-Kilobase Region and Are ...
Horizontal gene transfer (2nd ed.). Boston: Academic Press. pp. 81-91. ISBN 978-0-12-680126-2. Summers WC (1991). "From culture ...
Genes can sometimes be exchanged between species by horizontal gene transfer; new species can arise rapidly through ... Horizontal gene transfer between organisms of different species, either through hybridisation, antigenic shift, or reassortment ... Melcher, Ulrich (2001). "Molecular genetics: Horizontal gene transfer". Oklahoma State University. Archived from the original ... horizontal gene transfer (HGT) makes it difficult to define a species. All species definitions assume that an organism acquires ...
Syvanen, Michael; Kado, Clarence I. (2002). Horizontal Gene Transfer Academic Press. p. 405. ISBN 978-0126801262 Symonds, M.R.E ... Both gene duplication and lateral gene transfer have the capacity to bring about relatively large changes that are saltational ... Polyploidy, karyotypic fission, symbiogenesis and lateral gene transfer are possible mechanisms for saltational speciation. The ... "rate genes" or "controlling genes" that change early development and thus cause large effects in the adult phenotype. These ...
Richardson, Aaron O.; Palmer, Jeffrey D. (2007). "Horizontal Gene Transfer in Plants". Journal of Experimental Botany. 58 (1): ... Keeling, Patrick J.; Palmer, Jeffrey D. (2008). "Horizontal gene transfer in eukaryotic evolution". Nature Reviews Genetics. 9 ... mitochondrial DNA and during horizontal gene transfer. His former doctoral students include Thomas D. Bruns, a Professor at the ... 1993). "Phylogenetics of Seed Plants: An Analysis of Nucleotide Sequences from the Plastid Gene rbcL" (PDF). Annals of the ...
Further information: Horizontal gene transfer. Theobald noted that substantial horizontal gene transfer could have occurred ... 2005 tree of life shows many horizontal gene transfers, implying multiple possible origins. ... though the suggestion of substantial horizontal gene transfer during early evolution has led to questions about the monophyly ( ... The fact that only one such set of enzymes exists is convincing evidence of a single ancestry.[1][22] 6,331 genes common to all ...
"The case of horizontal gene transfer from bacteria to the peculiar dinoflagellate plastid genome". Mobile Genetic Elements. 3 ( ... 3 Gene content and protein synthesis *3.1 Chloroplast genome reduction and gene transfer ... "Endosymbiotic gene transfer and transcriptional regulation of transferred genes in Paulinella chromatophora". Molecular Biology ... Endosymbiotic gene transfer is how we know about the lost chloroplasts in many chromalveolate lineages. Even if a chloroplast ...
To counteract this 26 sets of horizontal and vertical Helmholtz coils are arranged around the inner surfaces of the tank. With ... To monitor and control the offline processes that analyze and transfer data, a set of software was sophisticatedly developed. ... Charles Kane and Eugene Mele (2019). Life sciences. *Cornelia Bargmann, David Botstein, Lewis C. Cantley, Hans Clevers, Titia ... These frames are connected to each other in both the vertical and horizontal directions. Then the whole support structure is ...
2005). Bioinformatics: A Practical Guide to the Analysis of Genes and Proteins (en inglés) (third edition ed.). Wiley. ISBN 0- ... Desenvolvéronse interfaces baseadas en SOAP e REST (Representational State Transfer, transferencia de estado representacional) ... Ao maior nivel, amplos segmentos cromosómicos experimentan duplicación, transferencia horizontal, inversión, transposición, ... 1993) A Hidden Markov Model that finds genes in E. coli DNA ... Serial Analysis of Gene Expression, Análise en serie da ...
Asexual reproduction, horizontal gene transfer. Asexual reproduction, horizontal gene transfer. Sexual and asexual reproduction ... and the presence of archaea-like genes in certain bacteria, such as Thermotoga maritima, from horizontal gene transfer.[78] The ... Archaea show high levels of horizontal gene transfer between lineages. Some researchers suggest that individuals can be grouped ... "Horizontal Gene Transfer Mediated by Plasmids". Plasmids: Current Research and Future Trends. Caister Academic Press. ISBN 978- ...
Bacteria do not have sexes, but they do transmit DNA by several kinds of horizontal gene transfer. This is how they share ... Reproduction and gene transfer[change , change source]. A bacterium reproduces (creates more bacteria) by dividing in half and ...
"Horizontal Gene Transfer Mediated by Plasmids". En Caister Academic Press. Plasmids: Current Research and Future Trends. ISBN ... "Bacterial type III secretion systems are ancient and evolved by multiple horizontal-transfer events". Gene 312: 151-63. PMID ... "Evidence for lateral gene transfer between Archaea and bacteria from genome sequence of Thermotoga maritima". Nature 399 (6734 ... 2002). "Introns in protein-coding genes in Archaea". FEBS Lett. 510 (1-2): 27-30. PMID 11755525. doi:10.1016/S0014-5793(01) ...
Keeling, PJ; Palmer, JD (August 2008). "Horizontal gene transfer in eukaryotic evolution.". Nature Reviews Genetics 9 (8): 605- ... "Further understanding human disease genes by comparing with housekeeping genes and other genes". BMC Genomics 7: 31. doi: ... Ochman, H; Lawrence, JG; Groisman, EA (18 May 2000). "Lateral gene transfer and the nature of bacterial innovation.". Nature ... Treangen, TJ; Rocha, EP (27 January 2011). "Horizontal transfer, not duplication, drives the expansion of protein families in ...
The queen shares half her genes with her sons and one-quarter with the sons of fertile female workers.[65] This pits the worker ... Nurse bees have the ability to selectively transfer sterols to larvae through brood food.[31] ... which is horizontal (not vertical, as in other species), and worker bees orient the dance in the actual compass direction of ... The worker shares half her genes with the drone and one-quarter with her brothers, favouring her offspring over those of the ...
Horizontal gene transfer. *Genomic island. *Transposable element *Class I or retrotransposon. *Class II or DNA transposon ... viable daughter cells to be produced would require an extra replication of the intact RNA gene homologous to any RNA gene that ... Similarly, tRNA is suggested to have evolved from RNA molecules that began to catalyze amino acid transfer.[37]. RNA in ... If at least one damage-free copy of each RNA gene is present in the transient diploid, viable progeny can be formed. For two, ...
... which explains evolution as the outcome of events such as mutations and horizontal gene transfer, which provide genetic ... Rocks normally form relatively horizontal layers, with each layer younger than the one underneath it. If a fossil is found ...
... en.wikipedia.org/wiki/Horizontal_gene_transfer Horisontaalne geeniülekanne].,/ref, Lähedaste liikide vahel toimib ... "DEVELOPMENT OF THE "GENE GUN" AT CORNELL". Retrieved 28th january 2010.].,/ref, ... rakkudes on põhjuseks, miks antud bakter taimedele kasvajaid tekitab.,ref,[Nester, Eugene. "Agrobacterium: The Natural Genetic ... growth hormone fusion genes". Nature 300 (5893): 611-5. doi:10.1038/300611a0. PMID 6958982].,/ref, Varajastel 1970. aastatel ...
Lobe (lobule) - attached or free according to a classic single-gene dominance relationship ... head-related transfer function, pinna notch). In various species, the pinna can also signal mood and radiate heat. ...
DellaSala, Gene (August 29, 2004). "Setting the Subwoofer / LFE Crossover for Best Performance". Tips & Tricks: Get Good Bass. ... A giant-magnetostrictive speaker exhibiting good acoustic characteristics when it is used while being placed on a horizontal ... and their output pattern is wide in the horizontal plane, a pattern that has convenient applications in concert sound.[26] ... Ferrofluid#Heat transfer. *Guitar speaker. *Headphones. *High-end audio. *Isobaric loudspeaker. *List of loudspeaker ...
... horizontal gene transfer. Other critics argue that there can be no "dual" inheritance without cultural inheritance being " ... Genes and culture continually interact in a feedback loop, changes in genes can lead to changes in culture which can then ... Genes constrain the brain's structure and, hence, the ability of the brain to acquire and store culture. Genes may also endow ... In other words, "memes" (ideas) are not like genes. Genes are copied faithfully as they are replicated, but ideas are not. It's ...
... analysis of unique domain architectures and phylogenetic trees reveals a complex history of horizontal gene transfer events". ... These are clear indications that horizontal transfer has occurred several times during the evolutionary history of aaRSs.[10][ ... TARS (gene). References[edit]. *^ McClain WH (November 1993). "Rules that govern tRNA identity in protein synthesis". Journal ... The novel domain additions to aaRS genes are accretive and progressive up the Tree of Life.[18][19][20] The strong evolutionary ...
the wave energy density per unit horizontal area is E. =. 1. 2. ρ. g. a. 2. ,. {\displaystyle \scriptstyle E={\frac {1}{2}}\rho ... As long as the waves propagate slower than the wind speed just above the waves, there is an energy transfer from the wind to ... where E is the mean wave energy density per unit horizontal area (J/m2), the sum of kinetic and potential energy density per ... leading to the factor 1⁄16 in the wave energy density per unit horizontal area.. ...
Horizontal gene transfer-emerging multidrug resistance in hospital bacteria». Acta pharmacologica Sinica. 24. 6. 519-526 or. ... Milioi urtero hamarnakatik ehunaka gene bikoizten dira.[42] Gene gehienek aurreko gene bateko eraldaketaz sortu direnez gene ... Lateral gene transfer in eukaryotes». Cellular and molecular life sciences. 62. 11. 1182-1197 or. ... DNA molekulan unitate funtzional bakar bat eratzen duten zatiei gene izena ematen zaie; gene ezberdinek base sekuentzia ...
"International team accelerates investigation of immune-related genes". The National Institute of Allergy and Infectious ... The Rosetta Stone was originally displayed at a slight angle from the horizontal, and rested within a metal cradle that was ... Eventually an agreement was reached, and the transfer of the objects was incorporated into the Capitulation of Alexandria ... had resulted in the transfer of Coele-Syria, including Judaea, from the Ptolemies to the Seleucids. Meanwhile, in the south of ...
This natural process of horizontal gene transfer in plants is being utilized as a tool for fundamental and applied research in ... Transfer is initiated at the right border and terminated at the left border and requires the vir genes of the Ti plasmid. The ... The same procedure of T-DNA transfer can be used to disrupt genes via insertional mutagenesis. Not only does the inserted T-DNA ... For example, this gene disruption strategy used for assigning functions to genes defined only by sequence helped to demonstrate ...
"Ancient Horizontal Gene Transfer" Nature Reviews Genetics 121-132. orr. 2003ko otsaila ... Organismo eukarioto gehienetan gene-aldakortasuna lortzen da mutazioen bidez eta ugalketa sexualaren bidez, non bi gene-multzo ... Izan ere emandako bakterio-espezie batean gene-aldakortasun maila -espeziearen gene aukera nahiko altua izan daiteke. ... Bakterio gehienek 1000-4000 gene izaten dituzte. Escherichia coli (E. coli) putaduna]]ak esate baterako, hobeto ezagutzen den ...
The gene encoding the cholera toxin was introduced into V. cholerae by horizontal gene transfer. Virulent strains of V. ... ToxT then directly activates expression of virulence genes that produce the toxins, causing diarrhea in the infected person and ... Furthermore, the researchers found the bacterium creates a hyperinfected state where genes that control biosynthesis of amino ... and two vaccines developed using the same transfer of technology-ShanChol (Shantha Biotec) and Euvichol (EuBiologics Co.), ...
Cetacean flukes are horizontal and move up and down, because cetacean spines bend the same way as in other mammals. ... Static tail fins are used as stabilizers Engineering fins are also used as heat transfer fins to regulate temperature in heat ... Shubin, N; Tabin, C; Carroll, S (1997). "Fossils, genes and the evolution of animal limbs" (PDF). Nature. 388 (6643): 639-648. ... Fins are also used to increase surface areas for heat transfer purposes, or simply as ornamentation. Fins first evolved on fish ...
"An exceptional horizontal gene transfer in plastids: gene replacement by a distant bacterial paralog and evidence that ... separate origins of EFL genes in haptophytes, photosynthetic cryptomonads, and goniomonads". Gene. 441 (1-2): 126-31. doi: ... "often dependent on the selection of taxa and gene data set".[3] Two 2012 studies produced opposite results.[3][5] ... "Extremely intron-rich genes in the alveolate ancestors inferred with a flexible maximum-likelihood approach". Mol. Biol. Evol ...
Rolling, F. (2004). "Recombinant AAV-mediated gene transfer to the retina: gene therapy perspectives". Gene Therapy. 11 (S1): ... Moreover, the horizontal action of the horizontal and amacrine cells can allow one area of the retina to control another (e.g. ... Curace Enrico M.; Auricchio Alberto (2008). "Versatility of AAV vectors for retinal gene transfer". Vision Research. 48 (3): ... "Safety and efficacy of gene transfer for Leber's congenital amaurosis". The New England Journal of Medicine. 358 (21): 2240- ...
This is because a male-determining gene (Mdmd) can be found on most or all housefly chromosomes.[67] Sexual differentiation is ... They can carry pathogens on their bodies and in their feces, contaminate food, and contribute to the transfer of food-borne ... Houseflies walk with a common gait on horizontal and vertical surfaces with three legs in contact with the surface and three in ... with sperm transfer, lasts for several minutes. Females normally mate only once and then reject further advances from males, ...
... horizontal gene transfer appears to be a potential mechanism for the adaptation of D. lykanthroporepellens to its ecological ... 1,771 genes were predicted, in which 1,720 were protein-coding genes and 51 were RNAs.[3] Putative function was designated to ... lykanthroporepellens was shown to have several rdhA and rdhB genes in the chromosome.[3] ... lykanthroporepellens is more closely related to the Dehalococcoides (class Dehalococcoidia) with 90% 16S rRNA gene sequence ...
Horizontal gene transfer. ReferencesEdit. *↑ "The Nobel Prize in Physiology or Medicine 1983". nobelprize.org. Retrieved 14 ...
Resistance is caused by newly acquired genetic traits (by mutation or horizontal gene transfer) that are heritable and confer ... Moyed HS, Bertrand KP (1983). "hipA, a newly recognized gene of Escherichia coli K-12 that affects frequency of persistence ... The best-understood persistence factor is the E. coli high persistence gene, commonly abbreviated as hipA. Although tolerance ... and only a few relevant genes have been identified to date. ...
... (or HGT) is the process of an organism acquiring another organisms DNA, usually through absorbing the ... Liverpool University recently conducted some research on Horizontal Gene Transfer. Sources. *Horizontal Gene Transfer and ... Horizontal Gene Transfer. News-Medical. 21 July 2019. ,https://www.news-medical.net/life-sciences/Horizontal-Gene-Transfer. ... Horizontal Gene Transfer. News-Medical. https://www.news-medical.net/life-sciences/Horizontal-Gene-Transfer.aspx. (accessed ...
To test whether these genes have been acquired from bacteria through horizontal gene transfer, firstly, the distribution of ... Horizontal gene transfer. The driving force behind the evolution of plant parasitic nematodes?. ... us clues for the function of a gene.. In this way we are able to silence nematode genes that are putative parasitism related, ... The use of octopamin was applied in gene silencing experiments, were nematodes were soaked in dubbel-stranded RNA and ...
Possible Mechanisms of Horizontal Gene Transfer. The mechanisms by which horizontal gene transfer takes place are largely a ... Horizontal gene transfer is the basis for the genetic engineering of commercially important crops, and natural horizontal gene ... These results indicate that natural mechanisms exist for the horizontal transfer of mt genes, suggesting that horizontal gene ... Although horizontal gene transfer is well documented in microbial genomes, no case has been reported in higher plants. We ...
Solution for horizontal gene transfer Explain why the rapid acquisition of antibiotic resistance by bacterial pathogens is ... horizontal gene transfer. Explain why the rapid acquisition of antibiotic resistance by bacterial pathogens is associated with ... horizontal gene transfer Explain why the rapid acquisition of antibiotic resistance by bacterial pathogens is associated with ... BiologyQ&A Libraryhorizontal gene transfer Explain why the rapid acquisition of antibiotic resistance by bacterial pathogens is ...
Target location during horizontal gene transfer. Genomes of living organisms are comprised of very long DNA molecules. A ... We address this question in the case of horizontal gene transfer processes such as viral transduction and conjugation, which ...
Analysis of Ten Brucella Genomes Reveals Evidence for Horizontal Gene Transfer Despite a Preferred Intracellular Lifestyle ... A Variety of Bacterial Pili Involved in Horizontal Gene Transfer Alain Filloux ... Mycobacterial Biofilms Facilitate Horizontal DNA Transfer between Strains of Mycobacterium smegmatis Kiet T. Nguyen, Kristina ... Rpn (YhgA-Like) Proteins of Escherichia coli K-12 and Their Contribution to RecA-Independent Horizontal Transfer Anthony W. ...
Zhaxybayeva, O., Gogarten, J. P. (2007) Horizontal gene transfer, gene histories and the root of the tree of life. In ... Hilario, E., Gogarten, J. P. (1993) Horizontal transfer of ATPase genes - the tree of life becomes a net of life. Biosystems 31 ... Jain, R., Rivera, M. C., Lake, J. A. (1999) Horizontal gene transfer among genomes: the complexity hypothesis. Proc Natl Acad ... In: Gogarten M.B., Gogarten J.P., Olendzenski L.C. (eds) Horizontal Gene Transfer. Methods in Molecular Biology, vol 532. ...
... of horizontal gene transfer has been shown to be responsible for widespread transfer among bacterial populations of genes ... showing mrfp1 gene expression, about 2 hours after the transfer of the mrfp1 gene. This expression of the mrfp1 gene was ... the fate of the transferred DNA, the global frequency of the horizontal gene transfer (versus the frequency of inheritance of ... Direct Visualization of Horizontal Gene Transfer. By Ana Babić, Ariel B. Lindner, Marin Vulić, Eric J. Stewart, Miroslav Radman ...
horizontal gene transfer Intelligent Design Horizontal gene transfer: Human gut microbes exchange genes more frequently in ... horizontal gene transfer. Cell biology Evolution horizontal gene transfer Intelligent Design Researchers: The last bacterial ... horizontal gene transfer Intelligent Design Plants Horizontal gene transfer between plants and insects acknowledged. So what ... horizontal gene transfer Intelligent Design Massive horizontal gene transfer in plants. Researchers: This union of two ...
Several genomic evidence suggest horizontal gene transfer (HGT) of mntH C genes: (i) The enterobacteria Wigglesworthia mntH ... Horizontal gene transfer of "prototype" Nramp in bacteria.. Richer E1, Courville P, Bergevin I, Cellier MF. ... identified in invertebrates represent a possible source for transfer of Nramp genes toward opportunistic bacteria. This study ... Eukaryotic Nramp genes encode divalent metal ion permeases important for nutrition and resistance to microbial infection. ...
Horizontal gene transfer/Draft. From Citizendium. , Talk:Horizontal gene transfer(Redirected from Talk:Horizontal gene transfer ... of core genes are transferred laterally." to "... only about 2% of core genes have been shown to have been transferred ... some of the genes could have come from horizontal gene transfer from now-extinct species. How about changing this sentence " ... But what does horizontal gene transfer have to do with politics? May some editor/author please explain. Thanks! Yi Zhe Wu 11:10 ...
... how a hosts gene regulatory environment can facilitate the establishment of a gene newly arrived via horizontal transfer. ... Studying the cellulose synthase gene in ascidians, originally derived from actinobacteria, the team showed that a GC-rich AP-2 ... binding site upstream of this gene must have been key to it becoming established. This enabled its epidermis-specific ... Mechanism of Successful Horizontal Gene Transfer between Divergent Organisms Explained (1 of 2) (IMAGE) view more ...
... evolutionists have resorted to the myth of pervasive horizontal gene transfer.. Horizontal gene transfer (HGT) is the process ... Another Horizontal Gene Transfer Fairy Tale by Jeffrey P. Tomkins, Ph.D. * Evidence for Creation › Evidence from Science › ... This is actually one of the few clearly documented cases of horizontal gene transfer showing that a specific type of parasite- ... This is due to the fact that the only cases where such gene transfer occurs in nature typically involves a clear host-parasite ...
We describe the reasons why the newly recognized process of horizontal gene transfer (HGT) forces evolutionists who study ... Species concept pluralism systematics horizontal gene transfer evolutionary units nested hierarchy This is a preview of ... In: Gogarten M.B., Gogarten J.P., Olendzenski L.C. (eds) Horizontal Gene Transfer. Methods in Molecular Biology, vol 532. ... We describe the reasons why the newly recognized process of horizontal gene transfer (HGT) forces evolutionists who study ...
In other words, it enhances horizontal gene transfer ... Horizontal gene transfer is the transfer of genetic material ... and horizontal gene transfer is one of the major considerations.. Some of us have argued that the hazards of horizontal gene ... Artificial vectors enhance horizontal gene transfer. *They are derived from natural genetic parasites that mediate horizontal ... What are the hazards of horizontal gene transfer?. Most artificial vectors are either derived from viruses or have viral genes ...
Horizontal gene transfer (HGT) (or Lateral gene transfer) is any process in which an organism gets genetic material from ... Integrons, a bacterial "kit" for transferring gene cassettes.. History[change , change source]. Horizontal gene transfer was ... Most thinking in genetics has focused on vertical transfer, but there is a growing awareness that horizontal gene transfer is a ... "Horizontal gene transfer in plants". Journal of Experimental Botany 58 (1): 1-9 [2]. doi:10.1093/jxb/erl148. PMID 17030541. ...
Studying the hotbed of horizontal gene transfers. For over 200,000 years, humans and their gut microbiomes have coevolved into ... Cross species transfer of genes has driven evolution. Far from just being the product of our parents, University of Adelaide ... New gene transfer rules could help prevent spread of antibiotic resistance. Unlike other organisms, bacteria can take up ... Microbes in the human body swap genes, even across tissue boundaries: study. Bacteria in the human body are sharing genes with ...
Many horizontal gene transfer processes, including conjugation, transformation, transduction via bacteriophages have been shown ... Many bioinformatical and microbiomic analyses have also been performed to elucidate AMR transfer dynamics. Despite these ... to play key roles in the dissemination of AMR, which is usually encoded by antimicrobial resistance genes (ARGs) carried by ... Horizontal gene transfer processes for AMR dissemination and the regulatory mechanisms for AMR dissemination.. • Mobile genetic ...
Horizontal gene transfer (HGT) is the transfer of genetic material across species boundaries and has been a driving force in ... Horizontal gene transfer (HGT) is the nonsexual transfer and genomic integration of genetic materials between organisms. In ... Massive horizontal gene transfer in Orobanchaceae. Zhenzhen Yang, Yeting Zhang, Eric K. Wafula, Loren A. Honaas, Paula E. Ralph ... Massive horizontal gene transfer in Orobanchaceae. Zhenzhen Yang, Yeting Zhang, Eric K. Wafula, Loren A. Honaas, Paula E. Ralph ...
In other words, it enhances horizontal gene transfer ... Horizontal gene transfer is the transfer of genetic material ... The hazards of horizontal gene transfer are summarized in Box 2. Box 2 Potential hazards of horizontal gene transfer from ... Artificial vectors greatly enhance horizontal gene transfer (see Box 1) [14]. Box 1 Artificial vectors enhance horizontal gene ... Horizontal gene transfer. may spread transgenes to the entire biosphere *Genetic engineering is unregulated horizontal gene ...
Associations of Gene Transfer, Horizontal with chemical compounds. *Phylogenetic analysis suggests horizontal gene transfer of ... Simultaneous horizontal gene transfer of a gene coding for ribosomal protein l27 and operational genes in Arthrobacter sp. ... Gene context of Gene Transfer, Horizontal. *Our data suggest that bacterial GlnRS has a eukaryotic origin and was acquired by a ... Disease relevance of Gene Transfer, Horizontal. *In addition, comparison of the sequence of the atpCAB genes of S. pneumoniae ...
Horizontal gene transfer (HGT) plays a major role in the spread of antibiotic resistance. Of particular concern are ... Inter-species population dynamics enhance microbial horizontal gene transfer and spread of antibiotic resistance.. Cooper RM1, ... Inter-species population dynamics enhance microbial horizontal gene transfer and spread of antibiotic resistance ... Inter-species population dynamics enhance microbial horizontal gene transfer and spread of antibiotic resistance ...
... in particular horizontal gene transfer, where DNA is transferred from one organism to another, resulting in an organisms ... We found that for SlopeTree and all other whole-genome methods we applied, horizontal transfer causes some evolutionary ... in contrast to the more traditional methods which used single genes earlier and now typically use groups of conserved genes. ... developed a new whole-genome method for estimating evolutionary distances which identifies and corrects for horizontal transfer ...
Following this discovery, it was therefore of interest to examine the extent and possible routes of horizontal gene transfer ( ... Following this discovery, it was therefore of interest to examine the extent and possible routes of horizontal gene transfer ( ... CODH genes and gene clusters that include [Ni,Fe]-CODHs.The genome sequence of the extreme thermophile Thermosinus ... CODH genes and gene clusters that include [Ni,Fe]-CODHs. The genome sequence of the extreme thermophile Thermosinus ...
tags: horizontal gene transfer x immunology x developmental biology x The Scientist. » horizontal gene transfer, immunology and ...
The Genes of Parkinsons Disease. By Bobby Thomas and M. Flint Beal , February 1, 2011 ... Small trials using younger donors and elderly recipients hint that mesenchymal stem cell transfers might reduce frailty. ... tags: horizontal gene transfer x neuroscience x The Scientist. » horizontal gene transfer and neuroscience ...
... Alejandra ... A. C. Martiny, Y. Huang, and W. Li, "Occurrence of phosphate acquisition genes in Prochlorococcus cells from different ocean ... A. C. Martiny, M. L. Coleman, and S. W. Chisholm, "Phosphate acquisition genes in Prochlorococcus ecotypes: evidence for genome ...
Gene duplication and subfunctionalization, as well as horizontal gene transfer are proposed mechanisms in the evolution of ... Our results support an ancient horizontal gene transfer event from an actinobacterial source into ascomycete fungi, followed by ... interkingdom horizontal gene transfer has been evoked as the most likely evolutionary scenario. However, the origin of the ... genes and the direction of the transfer remained elusive. Methodology/Principal Findings We used comparative phylogenetics to ...
Unlike vertical gene transfer, such as the transfer of DNA from parent to child, horizontal gene transfer occurs between ... was made possible when genes from soil bacteria were transferred to algae through a process called horizontal gene transfer. ... Horizontal gene transfer: The surprising trick bacteria uses to render drugs useless ... "These algae mingled with and received key genes from soil bacteria that helped them and their descendants to cope with the ...
Citizendium:Horizontal gene transfer Citizendium:Horizontal gene transfer in prokaryotes Citizendium:Horizontal gene transfer ... Barlow M (2009). "What antimicrobial resistance has taught us about horizontal gene transfer". Horizontal Gene Transfer. ... Horizontal gene transfer (HGT) or lateral gene transfer (LGT) is the movement of genetic material between unicellular and/or ... Plants are capable of receiving genetic information from viruses by horizontal gene transfer. Horizontal transfer occurs from ...
  • However, even when the two organisms in question are in close proximity to each other, such as in a symbiotic or parasitic relationship, the transfer of genetic material and its introduction into a new genome only marks the initial step for successful horizontal gene transfer. (eurekalert.org)
  • The major problem with claiming that these alleged HGT genes are imported or 'foreign' (i.e., transferred into the genome from some other creature), is that many of them encode important enzymatic proteins and are key parts of the interconnected gene networks and complex biochemical pathways that are essential to the very life of the organism. (icr.org)
  • Not only that, but the cells of the germline (those that produce sperm and egg) must be specifically targeted or the introgressed genes (those that were incorporated from one species into the genome of another) will not be inherited. (icr.org)
  • Distinct types of rRNA operons exist in the genome of the actinomycete Thermomonspora chromogena and evidence for horizontal gene transfer of an entire rRNA operon. (wikipedia.org)
  • For horizontal gene transfer to be successful, the foreign genetic material must become integrated into the cell s genome, or become stably maintained in the recipient cell in some other form. (ratical.org)
  • Divergent tetranucleotide frequency and codon usage showed that the gene cluster of T. carboxydivorans that encodes a [Ni,Fe]-CODH and an energy-converting hydrogenase is dissimilar to its whole genome but is similar to the genome of the phylogenetically distant Firmicute, Carboxydothermus hydrogenoformans . (frontiersin.org)
  • A. C. Martiny, M. L. Coleman, and S. W. Chisholm, "Phosphate acquisition genes in Prochlorococcus ecotypes: evidence for genome-wide adaptation," Proceedings of the National Academy of Sciences of the United States of America , vol. 103, no. 33, pp. 12552-12557, 2006. (hindawi.com)
  • Grafting of one plant to another can transfer chloroplasts (organelles in plant cells that conduct photosynthesis), mitochondrial DNA, and the entire cell nucleus containing the genome to potentially make a new species. (wikipedia.org)
  • By analyzing the pool of genes in the microbial community of the L. villosa beetles, Jason Kwan and his team at the University of Wisconsin in Madison, USA, identified the genes responsible for the production of lagriamide in the genome of the dominant beetle symbiont. (uncommondescent.com)
  • Just to be precise, the putative gene cluster which could be responsible for the synthesis of the antifungal molecule, consisting of 13 different genes, is in the genome of the symbiont bacterium, and the possible HGT is therefore HGT between bacterial strains. (uncommondescent.com)
  • An intermediate view is that HGT occurs frequently between bacterial lineages, contributing various strain-specific genes and thereby increasing the pan-genome of a bacterial species, but that the bacterium's core genome is inherited vertically and rarely perturbed by HGT ( 15 , 41 , 50 , 51 , 58 ). (asm.org)
  • How bdelloids have been able to gobble up such a variety of genes from their environment and incorporate it into their genome is a good question. (scienceagogo.com)
  • In this paper, we investigate horizontal gene transfer in the human genome. (pubmedcentralcanada.ca)
  • These human genome regions involve 642 known genes, which are enriched with ion binding. (pubmedcentralcanada.ca)
  • Compared to known horizontal gene transfer regions in the human genome, there were few overlapping regions, which indicated horizontal gene transfer is more common than we expected in the human genome. (pubmedcentralcanada.ca)
  • Horizontal gene transfer impacts hundreds of human genes and this study provided insight into potential mechanisms of HGT in the human genome. (pubmedcentralcanada.ca)
  • Genome-wide comparative and phylogenetic analyses show that HGT in animals typically gives rise to tens or hundreds of active 'foreign' genes, largely concerned with metabolism. (pubmedcentralcanada.ca)
  • This review focuses on vibrio ecology and genome plasticity, which confers an ability to adapt to new niches and is driven, at least in part, by horizontal gene transfer (HGT). (epfl.ch)
  • The M. schaedleri genome has been shaped by extensive horizontal gene transfer, primarily from intestinal Epsilon - and Deltaproteobacteria , indicating that horizontal gene transfer has played a key role in defining its niche in the gut ecosystem. (unl.edu)
  • These genes are additional to existing core genome copper resistance mechanisms, and are not found in typical S. aureus lineages, but are increasingly identified in emerging pathogenic isolates. (findaphd.com)
  • Bacterial adaptation is accelerated by the acquisition of novel traits through horizontal gene transfer, but the integration of these genes affects genome organization. (pasteur.fr)
  • This concentration increases with genome size and with the rate of transfer. (pasteur.fr)
  • Hotspots concentrate most changes in gene repertoires, reduce the trade-off between genome diversification and organization, and should be treasure troves of strain-specific adaptive genes. (pasteur.fr)
  • Overrepresentation of hotspots with fewer mobile genetic elements in naturally transformable bacteria suggests that homologous recombination and horizontal gene transfer are tightly linked in genome evolution.Horizontal gene transfer (HGT) is an important mechanism for genome evolution and adaptation in bacteria. (pasteur.fr)
  • The successful integration and expression of the transferred genes in this genome has changed the genetic and metabolic repertoire of the parasite. (biomedcentral.com)
  • Of the four tae genes found in bacterial species, three have been transferred to one or another eukaryotic genome. (evmedreview.com)
  • Horizontal gene transfer appears to be influencing only some taxa and some mitochondrial genes, thus indicating that the process is acting at the single gene (not whole genome) level. (uzh.ch)
  • We constructed a phylogeny for all 1689 genes identified and all homolog groups available from the rice ( Oryza sativa ) genome (3177 gene families) and used these to define 14 candidate plant-fungi HGT events. (plantcell.org)
  • We propose that transcriptional overshooting allows genome rebooting after horizontal gene transfer, and might have an adaptive role in overcoming the opposing demands of multilevel selection. (prolekare.cz)
  • Horizontal gene transfer Any process in which a bacterium inserts genetic material into the genomes of other pathogens or into the genome of its host. (mpkb.org)
  • Better Genome Editing for Bioenergy CRISPR-Cas9 is a powerful, high-throughput gene-editing tool that can help scientists engineer organisms for bioenergy applications. (doe.gov)
  • The genomes of w Bol1-b and w Pip are similar in genomic organisation, sequence and gene content, but show substantial differences at some rapidly evolving regions of the genome, primarily associated with prophage and repetitive elements. (biomedcentral.com)
  • We identified 44 genes in w Bol1-b that do not have homologs in any previously sequenced strains, indicating that Wolbachia 's non-core genome diversifies rapidly. (biomedcentral.com)
  • Whole genome sequencing of one species confirmed the presence of these foreign genes in the genome. (biomedcentral.com)
  • In the German outbreak bacteria, as in most E. coli , plenty of horizontal transfer has gone on to create the genome we are now looking at. (biofortified.org)
  • Evolution of Gene Fusions: Horizontal Transfer Versus Independent Events" Genome Biology 3(5): research0024.1-research0024.13. (bu.edu)
  • T4SSs mediate horizontal gene transfer, thus contributing to genome plasticity and the evolution of pathogens through dissemination of antibiotic resistance and virulence genes. (ox.ac.uk)
  • [3] However, no genes from the plant were expressed in the bacterial genome. (inhisimage.blog)
  • It rather represents a genome fusion between a beta and a gammaproteobacterium, followed by massive rearrangements and loss of redundant genes, leading to an unprecedented evolutionary collage. (nature.com)
  • Any part of the bacterial genome can be transferred can be transferred. (istudy.pk)
  • Life at the level of single cells is subject to unavoidable fluctuations in gene expression, and cells having the same genome may behave rather differently. (weizmann.ac.il)
  • Although horizontal gene transfer is well documented in microbial genomes, no case has been reported in higher plants. (pnas.org)
  • The second intron of the nad1 gene, located between exons b and c, is a group II intron (ref. 11 and Fig. 1 A ). Group II introns are self-splicing RNAs that are typical components of contemporary organellar genomes in plants, algae, fungi, protists, and eubacteria ( 10 , 12 - 14 ). (pnas.org)
  • The article in the link you provided seems to suggest that some researchers compared 40 genomes and found 2% of the genes seemed to be explained by HGT. (citizendium.org)
  • Earlier in my career, I participated in a study (published in the journal Science ), in which we found that the pathogenic bacterium Wolbachia had transferred large portions of its DNA into the genomes of both worms and insects. (icr.org)
  • Horizontal gene transfer is the transfer of genetic material between cells or genomes belonging to unrelated species, by processes other than usual reproduction. (i-sis.org.uk)
  • Currently, 185 out of 2887, or 6% of sequenced bacterial and archaeal genomes possess at least one gene encoding [Ni,Fe]-CODH, the key enzyme for anaerobic CO utilization. (frontiersin.org)
  • Many genomes encode multiple copies of [Ni,Fe]-CODH genes whose functions and regulation are correlated with their associated gene clusters. (frontiersin.org)
  • As Jian, Rivera and Lake (1999) put it: "Increasingly, studies of genes and genomes are indicating that considerable horizontal transfer has occurred between prokaryotes" (see also Lake and Rivera, 2007). (wikipedia.org)
  • Also, as HGT can bring into genomes radically different genotypes from distant lineages, or even new genes bearing new functions, it is a major source of phenotypic innovation and a mechanism of niche adaptation. (wikipedia.org)
  • In any case it is now clear that horizontal gene transfer has been and continues to be a strong and important force in the evolution of bacterial genomes. (asmscience.org)
  • Most of the foreign genes that Arkhipova found in the bdelloid genomes were clustered near the tips of chromosomes, called the telomeres. (scienceagogo.com)
  • Applying this new tool to the Aspergillus fumigatus , Aspergillus flavus , and Aspergillus nidulans genomes, we found 273, 542, and 715 transferred genes (HTGs), respectively. (mdpi.com)
  • Gene clustering analysis showed that 61%, 41% and 74% of HTGs in the three genomes form physically linked gene clusters (HTGCs). (mdpi.com)
  • It mainly concerned developing a program that reads in the sequences of all genes present on a specified set of bacterial genomes and then creates clusters of related genes. (sharcnet.ca)
  • They speculated that bacterial effector proteins transferred to target cells via Type VI secretion systems might be especially effectively maintained in eukaryotic genomes. (evmedreview.com)
  • Here, we compare the genomes of six plant species with those of 159 prokaryotic and eukaryotic species and identify 1689 genes that show the highest similarity to corresponding genes from fungi. (plantcell.org)
  • By analyzing 21 Escherichia genomes, we confirm that genes coding for secreted proteins-the secretome-are very frequently lost and gained and are associated with mobile elements. (uzh.ch)
  • One hypothesis posits that HGT can restore genes inactivated by mutations and thereby prevent stochastic, irreversible deterioration of genomes in finite populations known as Muller's ratchet. (g3journal.org)
  • Because genes involved in these mechanisms reside in the genomes of mobile genetic elements, transduction and conjugation can be considered side effects of the selfish propagation of these infectious agents ( Redfield 2001 ). (g3journal.org)
  • Bdelloid rotifers are microscopic animals that contain a higher proportion of horizontally transferred, non-metazoan genes in their genomes than typical of animals. (biomedcentral.com)
  • For approximately half of the fusions, stand-alone forms of the fusion components are encoded by juxtaposed genes, which are known or predicted to belong to the same operon in some of the prokaryotic genomes. (bu.edu)
  • Analysis of the growing number of available fully-sequenced genomes has shown that Horizontal Gene Transfer (HGT) in eukaryotes is more common than previously thought. (nottingham.ac.uk)
  • Using other approaches based on phylogenetic and linkage disequilibrium analysis we analyzed 24 genomes of M. tuberculosis complex isolates and found an excess of genetic diversity in regions encoding key adaptive functions including the type VII secretion system and the ancient horizontally transferred virulence-related regions carrying Rv0986 and Rv0987 genes above described. (pasteur.fr)
  • Although several genomes of amoebozoan species have been sequenced, little is known about the phyletic distribution of globin genes within this phylum. (ijbs.com)
  • Only two flavohemoglobins (FHbs) of D. discoideum have been reported and characterized previously while the genomes of Entamoeba species are apparently devoid of globin genes. (ijbs.com)
  • Additional FHb genes were identified in the genomes of four social amoebas and the true slime mold Physarum polycephalum . (ijbs.com)
  • Conjugation machinery offers an efficient method for acquisition of AMR and virulence genes, which may be responsible for propelling the evolution of pathogenic bacteria. (k-state.edu)
  • These results demonstrate the applicability of generating competitive analogues of CSPs as drugs to control horizontal transfer of antibiotic resistance and virulence genes, and to attenuate virulence during infection by S. pneumoniae . (prolekare.cz)
  • Kat also provides a reliable commentary of how several virulence genes were added to the outbreak strain's disease-ability armoury from various bacterial viruses and plasmids. (biofortified.org)
  • Learning more about the biochemical processes behind HGT is massively important, especially to the pharmaceutical industry, as a majority of antibiotic resistant species developments are attributed to horizontal gene transfer. (news-medical.net)
  • During work on the phylogeny of Gnetum , we developed specific primers to amplify the second intron in the nad1 gene, plus flanking exons, from numerous previously unstudied species of Gnetum . (pnas.org)
  • Researchers: Overall, we showed that LGT is a widespread phenomenon in grasses that has moved functional genes across the grass family into domesticated and wild species alike. (uncommondescent.com)
  • At Quanta: "Davis' team estimated that at least 1.2% of the plant's genes came from other species, particularly its hosts, past and present. (uncommondescent.com)
  • Furthermore, some of the genes could have come from horizontal gene transfer from now-extinct species. (citizendium.org)
  • In other words, it enhances horizontal gene transfer the direct transfer of genetic material to unrelated species. (i-sis.org.uk)
  • Some of us have argued that the hazards of horizontal gene transfer to unrelated species are inherent to genetic engineering(4). (i-sis.org.uk)
  • Bacteria have been known to exchange genes across species barriers in nature. (i-sis.org.uk)
  • By contrast, vertical transfer occurs when an organism gets genetic material from its ancestor , e.g., its parent or a species from which it has evolved. (wikipedia.org)
  • Horizontal gene transfer was first described in Japan in a 1959 publication that demonstrated the transfer of antibiotic resistance between different species of bacteria . (wikipedia.org)
  • Inter-species population dynamics enhance microbial horizontal gene transfer and spread of antibiotic resistance. (nih.gov)
  • 2013). Here, we show bacterial predation by Acinetobacter baylyi increases cross-species HGT by orders of magnitude, and we observe predator cells functionally acquiring adaptive resistance genes from adjacent prey. (nih.gov)
  • The plant Lophophytum pilfers mitochondrial genes from the species it parasitizes. (the-scientist.com)
  • Unlike vertical gene transfer, such as the transfer of DNA from parent to child, horizontal gene transfer occurs between different species. (sott.net)
  • Genes responsible for antibiotic resistance in one species of bacteria can be transferred to another species of bacteria through various mechanisms of HGT such as transformation, transduction and conjugation, subsequently arming the antibiotic resistant genes' recipient against antibiotics. (wikipedia.org)
  • Inter-bacterial gene transfer was first described in Japan in a 1959 publication that demonstrated the transfer of antibiotic resistance between different species of bacteria. (wikipedia.org)
  • The Rice researchers suggest that the speed of evolution has increased over time thanks to horizontal gene transfer, where bacteria and viruses exchange transposable chunks of DNA between species, thus making it possible for life forms to evolve faster than they would if they relied only on sexual selection or random genetic mutations. (scienceagogo.com)
  • Horizontal gene transfer (HGT) is a cross-species form of genetic transfer. (scienceagogo.com)
  • Sequence composition-based ("parametric") methods search for deviations from the genomic average whereas evolutionary history-based ("phylogenetic") approaches identify genes whose evolutionary history significantly differs from that of the host species. (wikipedia.org)
  • This lends them the ability to better characterize the HGT events they infer-notably by designating the donor species and time of the transfer. (wikipedia.org)
  • Finally, the computational costs of reconstructing many gene/species trees can be prohibitively expensive. (wikipedia.org)
  • Horizontal gene transfer (HGT) is thought to occur frequently in bacteria in nature and to play an important role in bacterial evolution, contributing to the formation of new species. (asm.org)
  • Three hundred three luminous strains, most of which were recently isolated from nature and which represent 11 Aliivibrio , Photobacterium , and Vibrio species, were screened for incongruence of phylogenies based on a representative housekeeping gene ( gyrB or pyrH ) and a representative lux gene ( luxA ). (asm.org)
  • In nearly all cases, housekeeping gene and lux gene phylogenies were congruent, and there was no instance in which the lux genes of one luminous species had replaced the lux genes of another luminous species. (asm.org)
  • In none of these cases of apparent HGT, however, did acquisition of the lux genes correlate with phylogenetic divergence of the recipient strain from other members of its species. (asm.org)
  • Prokaryotic organisms share genetic material across species boundaries by means of a process known as horizontal gene transfer (HGT). (sciweavers.org)
  • Phylogeny-based detection of HGT is one of the most commonly used approaches for this task, and is based on the fundamental fact that HGT may cause gene trees to disagree with one another, as well as with the species phylogeny. (sciweavers.org)
  • Hence, methods that adopt this approach compare gene and species trees, and infer a set of HGT events to reconcile the differences among these trees. (sciweavers.org)
  • In particular, we show the effect of inaccuracies in the reconstructed (species and gene) trees on inferring the correct number of HGT events. (sciweavers.org)
  • An alternative mechanism of gene acquisition is through horizontal gene transfer (HGT), which involves movement of genetic materials between different species. (pubmedcentralcanada.ca)
  • A proposed mechanism to explain the similarity of sequences between two species with a very distant common ancestor was horizontal gene transfer [ 9 ]. (pubmedcentralcanada.ca)
  • We found that transferred genes are concentrated in only ~1% of the chromosomal regions (hotspots) in 80 bacterial species. (pasteur.fr)
  • Here, using PCR with degenerate primers, we have successfully isolated ACC deaminase genes from a range of both gram-positive and gram-negative bacterial species. (asm.org)
  • Third, the authors acquired evidence for expression of the dae genes in a species of ameba. (evmedreview.com)
  • They also found previously published evidence for dae gene expression in a species of lancelet, a small marine organism. (evmedreview.com)
  • did not find any evidence for transfer of bacterial housekeeping amidases to eukaryotic species. (evmedreview.com)
  • Horizontal gene transfer (HGT) describes the transmission of genetic material across species boundaries and is an important evolutionary phenomenon in the ancestry of many microbes. (plantcell.org)
  • These data also suggest either that this bacterial species is particularly permissive for eukaryote-to-prokaryote gene transfers, or that these transfers may be more common than previously believed. (biomedcentral.com)
  • If so, we expect that species should differ in their complement of foreign genes, rather than sharing the same set of foreign genes inherited from a common ancestor. (biomedcentral.com)
  • Furthermore, there should be more foreign genes in species that desiccate more frequently. (biomedcentral.com)
  • Transcriptomes of all four species contain many genes with a closer match to non-metazoan genes than to metazoan genes. (biomedcentral.com)
  • Nearly half of foreign genes are shared between all four species and an outgroup from another family, but many hundreds are unique to particular species, which indicates that HGT is ongoing. (biomedcentral.com)
  • However, HGT still contributed hundreds of foreign genes to the species from permanently aquatic habitats. (biomedcentral.com)
  • We found evidence of differential loss of ancestral foreign genes previously associated with desiccation protection in the two non-desiccating species. (biomedcentral.com)
  • Clustering of fusion components from phylogenetically distant species was construed as evidence of dissemination of the fused genes by horizontal transfer. (bu.edu)
  • These findings suggest a major role for horizontal transfer of gene fusions in the evolution of protein-domain architectures, but also indicate that independent fusions of the same pair of domains in distant species is not uncommon, which suggests positive selection for the multidomain architectures. (bu.edu)
  • Species phylogenies built from the comparison of gene sequences suffer from two major limitations: on one side the true gene trees may differ from the species trees, and on the other side, the signal contained in the gene sequences might be too weak or too complex to be correctly interpreted by bioinformatics methods. (biomedcentral.com)
  • Gene trees will differ from species trees in cases of hidden paralogy, closely spaced cladogenesis events or horizontal gene transfers (HGT). (biomedcentral.com)
  • Many of the antibiotic resistance genes are carried on plasmids, transposons or integrons that can act as vectors that transfer these genes to other members of the same bacterial species, as well as to bacteria in another genus or species. (msu.edu)
  • Tuberculosis was initially considered as a clonal population with no known acquisition of genetic material by horizontal genetic transfer, although it carries IS elements with similarity to IS elements from other species. (pasteur.fr)
  • Thanks to a screening of M. tuberculosis transposon mutants impaired in the in vivo growth in macrophages we have identified a genetic region likely acquired by horizontal transfer from another bacterial species. (pasteur.fr)
  • We investigated eleven amoebozoan species for the presence of globin genes by genomic and phylogenetic in silico analyses. (ijbs.com)
  • Here, we present the first comprehensive multi-species analysis of E/HGT of genes encoding metabolic enzymes from bacteria to unicellular eukaryotes. (biomedcentral.com)
  • Horizontal gene transfer, the acquisition of genes across species boundaries, is a major source of novel phenotypes that enables microbes to rapidly adapt to new environments. (biomedcentral.com)
  • Horizontal gene transfer (HGT) is the lateral transfer of genetic material between different individuals and species, and a major driver of evolution in all domains of microbial life [ 1 , 2 , 3 ]. (biomedcentral.com)
  • The success, or failure, of an HGT event is largely determined by the effect of the transferred gene on the fitness (differential growth compared to the wild-type not carrying a transferred gene) of the recipient species. (biomedcentral.com)
  • Gene sharing among organisms of different species has been a prominent topic of discussion among the scientific community for the last few decades. (inhisimage.blog)
  • Pneumococcal surface adhesin A (psaA) gene is universally confirmed as one of the Streptococcus pneumoniae adhesion genes, but it is disputed whether the psaA gene is a Streptococcus pneumoniae species-specific gene. (semanticscholar.org)
  • however, high-frequency horizontal psaA gene transfer and recombination occurred in the other species of the streptococcus mitis group. (semanticscholar.org)
  • These findings confirmed that the psaA gene was not a Streptococcus pneumoniae species-specific gene, and high-frequency HGT and recombination events may explain the presence of the psaA gene in the other species of the streptococcus mitis group. (semanticscholar.org)
  • In a previous study, we detected a trp B gene of gammaproteobacterial origin in ' Ca. Tremblaya phenacola' from two Phenacoccus species, apparently indicating an unusual case of horizontal gene transfer (HGT) in a bacterial endosymbiont. (nature.com)
  • Sandu C., Chiribau C. B., Sachelaru P., Brandsch R. (2005) Plasmids for nicotine-dependent and -independent gene expression in Arthrobacter nicotinovorans and other Arthrobacter species. (uni-freiburg.de)
  • A clinical isolate of Staphylococcus epidermidis harbors a CRISPR spacer that matches the nickase gene present in nearly all staphylococcal conjugative plasmids. (nih.gov)
  • This animation shows how bacteria exchange genes on small pieces of DNA called plasmids through a process called horizontal gene transfer. (yourgenome.org)
  • Bacteria are able to exchange genes by the transfer of these plasmids in a process called horizontal gene transfer. (yourgenome.org)
  • The most worrying trend is the horizontal transmission of antibiotic resistance genes via mobile elements such as plasmids and transposons, especially in Gram-negative pathogens ( 1 - 3 ). (asm.org)
  • This ability makes BHR plasmids efficient shuttles for HGT, clearly illustrated in the last decades by their leading role in the spread of antibiotic resistance genes among microbial populations [2] . (prolekare.cz)
  • Competition between plasmid copies within a given cell favors plasmids with higher copy number, superior partition systems and higher transfer rates [9] . (prolekare.cz)
  • As a consequence, horizontal transfer promoted by agents such as plasmids, phages, or integrons drives microbial cooperation. (uzh.ch)
  • The mobile nature of… gene islands, transported between bacteria via plasmids or phages, creates the potential for acquired virulence in previously innocuous microbes," states researcher Dave Relman of Stanford University. (mpkb.org)
  • Conjugation and transduction involve transfer of prokaryotic DNA between cells mediated by infectious agents such as viruses and conjugative plasmids, respectively. (g3journal.org)
  • Conjugative gene exchange relies on mobile elements, such as plasmids, which transfer between donor and recipient cells. (uni-bielefeld.de)
  • These plasmids, when replicated, can be passed in whole or part to other bacteria by means of a process called conjugative transfer. (inhisimage.blog)
  • The rapid spread of antibiotic resistance genes in this manner is becoming medically challenging to deal with. (wikipedia.org)
  • This work will help shed light on many aspects of microbial evolution, including the adaptation of microbes to new ecological niches, evolution and spread of antibiotic resistance genes, the rise of emerging pathogens, and competition between microbes. (uconn.edu)
  • 8) According to Beaber et al , when Vibrio cholerae is exposed to the antibiotic ciprofloxacin, it will actually promote the spread of antibiotic resistance genes. (mpkb.org)
  • The acquisition and spread of antibiotic resistance genes in S. pneumoniae is at least partly due to genetic transformation, which occurs when the bacteria enter the competent state [7] - [9] . (prolekare.cz)
  • Surprisingly, these nematode enzymes display strikingly similarities towards bacterial genes instead of eukaryotic ones. (wur.nl)
  • Among eukaryotic lineages, however, very few natural horizontal transfers have been reported, and none of them involve transfers across groups of seed plants. (pnas.org)
  • Eukaryotic Nramp genes encode divalent metal ion permeases important for nutrition and resistance to microbial infection. (nih.gov)
  • Given the importance of gene transfers in eukaryotic evolution and the potential implications for chemotherapy, it is important to identify the complement of transferred genes in Cryptosporidium . (biomedcentral.com)
  • 2014) presents a fascinating study of examples in which bacterial genes have found their way to a number of distinct eukaryotic lineages including ticks and mites, gastropod (e.g., snails and slugs) and bivalve mollusks (e.g. clams and oysters), and choanoflagellates (a subset of ptotozoans). (evmedreview.com)
  • If the proteins Dae lacked such secretion signals, it might be more plausible to argue that the genes may have bacterial origins but were not functional in their new eukaryotic hosts. (evmedreview.com)
  • The transfer of amidase-encoding genes from bacteria to eukaryotic organisms is not the first instance of such trans-kingdom horizontal gene transfer (HGT). (evmedreview.com)
  • Keeling and Palmer, 2008 ), suggesting that universal eukaryotic cellular features, such as the possession of linear chromatin-based chromosomes, intron-exon gene structures, and the nuclear envelope, are not barriers to HGT. (plantcell.org)
  • It has been proposed that genes with certain functions may be more prone to HGT than others, but we still have a very poor understanding of the selective forces driving eukaryotic HGT. (nottingham.ac.uk)
  • Here, we set out to assess whether D-amino acid racemases are commonly transferred to and between eukaryotic groups. (nottingham.ac.uk)
  • Enrichment in particular functional classes was particularly revealing: alongside plastid related processes and carbohydrate metabolism, this highlighted a number of pathways in eukaryotic parasites that are rich in enzymes encoded by transferred genes, and potentially key to pathogenicity. (biomedcentral.com)
  • In eukaryotic parasites, genes encoding enzymes that have been gained through horizontal transfer may be attractive drug targets if they are part of processes not present in the host, or are significantly diverged from equivalent host enzymes. (biomedcentral.com)
  • HGT that accompanies endosymbiosis, termed endosymbiotic gene transfer (EGT), was important in establishing the eukaryotic organelles: the mitochondria and plastids. (biomedcentral.com)
  • First, living inside eukaryotic cells renders some genes unnecessary, while others become redundant with functions provided by the host. (nature.com)
  • Allen, B. L., Steel, M. (2001) Subtree transfer operations and their induced metrics on evolutionary trees. (springer.com)
  • Marshall favors horizontal gene transfer as a key method of early development because ancestor-descendant evolution is a "very slow" (42:25) evolutionary process. (uncommondescent.com)
  • One issue is the fact that different creatures have unique sets of genes specific to their kind with no apparent evolutionary history. (icr.org)
  • First, the researchers found unique genes in a variety of fruit flies, worms, primates, and humans that had no clear evolutionary ancestry. (icr.org)
  • Scientists have previously termed these 'orphan genes'-a unique type of gene that provides a clear anti-evolutionary enigma I have discussed in previous reports. (icr.org)
  • In the mid-1980s, Syvanen suggested that lateral gene transfer not only had biological significance, but was involved in shaping evolutionary history from the beginning of life on Earth. (wikipedia.org)
  • To more clearly define if the branching patterns observed in the [Ni,Fe]-CODH trees are due to functional conservation vs. evolutionary lineage, the genomic context of the [Ni,Fe]-CODH gene clusters was examined, and superimposed on the phylogenetic trees. (frontiersin.org)
  • In the mid-1980s, Syvanen predicted that lateral gene transfer existed, had biological significance, and was involved in shaping evolutionary history from the beginning of life on Earth. (wikipedia.org)
  • As noted re an earlier story about bats, the finding also suggests that Darwinian claims about natural selection producing evolutionary changes should be tested against the possibility that the change was in fact caused by horizontal gene transfer. (uncommondescent.com)
  • Inferring horizontal gene transfer through computational identification of HGT events relies upon the investigation of sequence composition or evolutionary history of genes. (wikipedia.org)
  • Phylogenetic methods examine evolutionary histories of genes involved and identify conflicting phylogenies. (wikipedia.org)
  • Phylogenetic methods tend to be applied to genes or protein sequences as basic evolutionary units, which limits their ability to detect HGT in regions outside or across gene boundaries. (wikipedia.org)
  • Horizontal gene transfer (HGT), the acquisition of genes by a member of one bacterial lineage from another lineage, is widely believed to play a major role in bacterial evolutionary divergence and speciation ( 29 , 39 , 40 , 46 ). (asm.org)
  • There is strong genomic evidence that bacteria often acquire evolutionary novelties from outside their ancestral population by horizontal gene transfer. (mpkb.org)
  • Gene fusions can be used as tools for functional prediction and also as evolutionary markers. (bu.edu)
  • The evolutionary history of gene fusions was studied by phylogenetic analysis of the domains in the fused proteins and the orthologous domains that form stand-alone proteins. (bu.edu)
  • On many occasions, the evolutionary scenario also involves one or more secondary fissions of the fusion gene. (bu.edu)
  • Previously identified evolutionary barriers - gene function and the number of protein-protein interactions - did not predict the fitness effects of transferred genes. (biomedcentral.com)
  • While computational approaches have been successful in describing long-term barriers to horizontal gene transfer, our experimental results identified previously underappreciated barriers that determine the fitness effects of newly transferred genes, and hence their short-term eco-evolutionary dynamics. (biomedcentral.com)
  • Also, the evolutionary scenarios of these psaA genes in these streptococcus mitis group isolates were analyzed by a phylogenetic tree based on the housekeeping genes (sodA and rnpB) and psaA genes. (semanticscholar.org)
  • If the origin of the two copies in Gnetum could be traced, this might provide evidence for horizontal gene transfer, adding a new dimension to our understanding of group II intron evolution. (pnas.org)
  • Tsukuba, Japan - The transfer of genes from one organism to another is potentially a rapid way for evolution to occur and for complicated novel functions to emerge. (eurekalert.org)
  • Because of their unwavering commitment to evolution, all ideas about these cleverly designed and network-integrated gene sequences being engineered by a Creator are not considered-at least not openly. (icr.org)
  • The genes and gene-constructs created in genetic engineering have never existed in billions of years of evolution. (i-sis.org.uk)
  • GTAs transfer DNA so frequently that they may have an important role in evolution. (wikipedia.org)
  • Richardson and Palmer (2007) state: "Horizontal gene transfer (HGT) has played a major role in bacterial evolution and is fairly common in certain unicellular eukaryotes. (wikipedia.org)
  • Horizontal gene transfer is the primary mechanism for the spread of antibiotic resistance in bacteria, and plays an important role in the evolution of bacteria that can degrade novel compounds such as human-created pesticides and in the evolution, maintenance, and transmission of virulence. (wikipedia.org)
  • This review aims to give an overview of the major horizontal transfer mechanisms and their evolution and then demonstrate the human lower gastrointestinal tract as an environment in which horizontal gene transfer of resistance determinants occurs. (dovepress.com)
  • Although the transfer of genes is thought to be crucial in prokaryotic evolution, its existence in higher organisms, including animals, is less well established [ 7 - 9 ]. (pubmedcentralcanada.ca)
  • This analyses suggest that while fruit flies and nematodes have continued to acquire foreign genes throughout their evolution, humans and other primates have gained relatively few since their common ancestor [ 10 ]. (pubmedcentralcanada.ca)
  • In the case of Clades 10 and 12, horizontal gene transfer of plant cell wall degrading enzymes from bacteria and fungi has been implicated in the evolution of plant parasitism. (wur.nl)
  • Horizontal gene transfer was previously shown to be a phenomenon that has contributed to the evolution of plant parasitism among nematodes. (wur.nl)
  • Horizontal gene transfer rapidly changes bacterial genetic repertoire and contributes to bacterial evolution. (illinois.edu)
  • Horizontal gene transfer (HGT) is a major force driving bacterial evolution. (prolekare.cz)
  • Horizontal gene transfer (HGT) is a major factor in the evolution of prokaryotes. (g3journal.org)
  • Another is the source of the new surface attachment genes carried on another plasmid related to that found previously in an African strain EAEC E. coli 55989, but this changed during the last few years of evolution by gaining new surface attachment genes. (biofortified.org)
  • Fused genes often show a scattered phyletic distribution, which suggests a role for processes other than vertical inheritance in their evolution. (bu.edu)
  • This indicates that evolution of gene fusions often, if not always, involves an intermediate stage, during which the future fusion components exist as juxtaposed and co-regulated, but still distinct, genes within operons. (bu.edu)
  • We characterized the genes that supported each of these two hypotheses, and found that differences in rates of evolution or in amino-acid compositions could not explain the presence of two incongruent phylogenetic signals in the alignment. (biomedcentral.com)
  • This process is used by bacteria to acquire antibiotic resistance genes and is important for bacterial evolution. (meta.org)
  • Horizontal gene transfer (HGT) has played a key role in prokaryotic evolution and its importance in eukaryotes is increasingly evident. (biomedcentral.com)
  • The number of enzymes encoded by genes gained through E/HGT has been established, providing insight into functional gain during the evolution of unicellular eukaryotes. (biomedcentral.com)
  • HGT is likely to have had a more important influence upon the evolution of unicellular eukaryotes because there is no separate germline in which the transferred genes need to be fixed. (biomedcentral.com)
  • Transfer of genetic material to a being other than one of the donor's offspring. (citizendium.org)
  • The artificial constructs or transgenic DNA typically contain genetic material from bacteria, viruses and other genetic parasites that cause diseases as well as antibiotic resistance genes that make infectious diseases untreatable. (i-sis.org.uk)
  • They consist of genetic material originating from bacteria, viruses and other genetic parasites that cause diseases and spread drug and antibiotic resistance genes. (i-sis.org.uk)
  • Horizontal gene transfer (HGT) (or Lateral gene transfer ) is any process in which an organism gets genetic material from another organism without being the offspring of that organism. (wikipedia.org)
  • Bacterial conjugation , a process in which a bacterial cell transfers genetic material to another cell by cell-to-cell contact. (wikipedia.org)
  • Horizontal gene transfer (HGT) or lateral gene transfer (LGT) is the movement of genetic material between unicellular and/or multicellular organisms other than by the ("vertical") transmission of DNA from parent to offspring (reproduction). (wikipedia.org)
  • There are several mechanisms for horizontal gene transfer: Transformation, the genetic alteration of a cell resulting from the introduction, uptake and expression of foreign genetic material (DNA or RNA). (wikipedia.org)
  • However, this is one of the few examples in which there is direct evidence that such transfer of genetic material underlies the defensive potential of a symbiont. (uncommondescent.com)
  • 2010). One of the hazards accompanying consumption of GM- plants is the possible horizontal gene transfer (HGT) which is the transfer of genetic material directly to a living cell or an organism (van den Eede et al. (academicjournals.org)
  • AMR results from pathogenic strains of bacteria adapting to antimicrobial-containing environments through mutations or through horizontal gene transfer (HGT) of genetic material containing resistance genes. (k-state.edu)
  • They found that the intestinal bacteria genes were more than 90% homologous to the corresponding sequence in HIV - suggesting that the bacteria and the HIV virus had traded a significant amount of genetic material. (mpkb.org)
  • Selective constraints by themselves probably do not stimulate gene transfer (a possible exception is the regulation of conjugative transposition in Bacteroides [ 29 ]) but determine whether the organisms acquiring new genetic material will multiply and grow. (asm.org)
  • Horizontal gene transfer , or the process of swapping genetic material between neighboring "contemporary" bacteria, is another means by which resistance can be acquired. (msu.edu)
  • Horizontal gene transfer is a mechanism in which genetic material is transmitted from one organism to another organism. (meta.org)
  • Horizontal gene transfer is any transfer of genetic material between organisms that does not involve the vertical transmission to offspring. (inhisimage.blog)
  • In addition, the relative isolation of the endosymbiont populations usually hinders the possibility of acquiring genetic material through horizontal gene transfer (HGT). (nature.com)
  • They also found an exciting clue: these genes are located in a so called genomic island, i.e., a region that was likely inserted in the chromosome of the symbiont from an external source. (uncommondescent.com)
  • Horizontal or lateral gene transfer (HGT or LGT) is the transmission of portions of genomic DNA between organisms through a process decoupled from vertical inheritance. (wikipedia.org)
  • Genes encoding these toxins are well-studied, however the genomic content and organization of the CDC is not known. (7thspace.com)
  • In addition, rapid death of both antibiotic-resistant strains and destruction of plasmid and genomic DNA were observed on copper and copper alloy surfaces, which could be useful in the prevention of infection spread and gene transfer. (asm.org)
  • The w Bol1-b-specific genes we have identified provide candidates for further investigations of the genomic bases of phenotypic differences between closely-related Wolbachia strains. (biomedcentral.com)
  • Many display features typical of the genomic islands found in other bacteria, including residual material from mobile genetic elements, flanking direct repeats, insertion in the vicinity of tRNA sequences, and genes with putative or documented virulence functions. (pasteur.fr)
  • The most recently described GI type T4SSs play a key role in the horizontal transfer of a wide variety of genomic islands derived from a broad spectrum of bacterial strains. (ox.ac.uk)
  • In this way we are able to silence nematode genes that are putative parasitism related, and study their mode of action. (wur.nl)
  • We used a transcriptome-wide analysis to identify putative horizontal gene transfer events. (wur.nl)
  • Also of note, M. schaedleri harbors a type VI secretion system and putative effector proteins and can modify gene expression in mucosal tissue, suggesting intimate interactions with its host and a possible role in inflammation. (unl.edu)
  • Using the biochemical assay procedure, it was ascertained that all of these putative genes encoded functional ACC deaminase. (asm.org)
  • Putative functional annotation of the HGT candidate genes suggests that two fungi-to-plant transfers have added phenotypes important for life in a soil environment. (plantcell.org)
  • Second, the approach to supposedly identifying many of the foreign genes in animals as microbial in origin was not even based on actual complete gene sequence, but depended upon isolated regions of similarity in the proteins they encode. (icr.org)
  • In contrast, microbial genes are typically much less complex and lack these intricate and intervening regulatory regions found in animal genes. (icr.org)
  • The discovery of horizontal gene transfer is related to the introduction of experimental microbial genetics some 70 years ago. (mdpi.com)
  • Microbial ecologists and geneticists were forced to look at the natural environment to determine experimentally whether horizontal gene exchange could take place in nature. (asmscience.org)
  • Owing to a suite of newly available computational algorithms and experimental approaches, we have a broader understanding of the genes that are being transferred and are starting to understand the ecology of HGT in natural microbial communities. (cdc.gov)
  • Conjugation - a form of bacteria-to-bacteria DNA transfer, via direct contact. (news-medical.net)
  • We address this question in the case of horizontal gene transfer processes such as viral transduction and conjugation, which result in the rapid acquisition of new traits in bacteria. (weizmann.ac.il)
  • Conjugation allows bacteria to acquire genes for antibiotic resistance, novel virulence attributes, and alternative metabolic pathways. (sciencemag.org)
  • Together with transformation and phage-mediated transduction, conjugation is a key mechanism for horizontal gene transfer in bacteria ( 1 ). (sciencemag.org)
  • The F plasmid contains all the genes required for conjugation (e.g., mediating the contact between donor and recipient cells) and for regulation of DNA mobilization and its unidirectional transfer ( 3 ). (sciencemag.org)
  • In some cases, F can excise from the chromosome of Hfr, creating an F′ molecule that carries chromosomal genes as well as the conjugation genes ( 5 ). (sciencemag.org)
  • Many aspects of the mechanism and consequences of conjugation remain unresolved, including the role of the F pilus in DNA transfer during conjugation, the fate of the transferred DNA, the global frequency of the horizontal gene transfer (versus the frequency of inheritance of individual genetic markers), and the pattern of inheritance of donor DNA present in the initial transconjugant cell. (sciencemag.org)
  • This tool allowed us to quantify the ongoing transfer of DNA during conjugation and to acquire time-lapse movies that follow the fate of the newly acquired DNA in individual cells through any number of cell divisions. (sciencemag.org)
  • Horizontal gene transfer (HGT) in bacteria and archaea occurs through phage transduction, transformation, or conjugation, and the latter is particularly important for the spread of antibiotic resistance. (nih.gov)
  • Similar observations in the 1940s and 1950s showed evidence that conjugation and transduction are additional mechanisms of horizontal gene transfer. (wikipedia.org)
  • The three major mechanisms by which bacteria transfer genes horizontally are conjugation, natural transformation, and transduction. (dovepress.com)
  • Conjugation is the most studied mechanism of horizontal gene transfer in the human intestine or otherwise. (dovepress.com)
  • 5 - 7 Conjugation is the transfer of DNA fragments that can be very small, up to large chromosomes. (dovepress.com)
  • The general order of the events of conjugation is a) cell-to-cell contact, b) mating pair formation, and finally c) transfer of plasmid DNA through a conjugative pilus. (dovepress.com)
  • The conjugation frequency was approximately 10 to 50 times greater and occurred immediately, and resulting transconjugants were more stable with ESBL E. coli as the donor cell than with K. pneumoniae , but bla NDM-1 transfer increased with time. (asm.org)
  • Conjugation occurred in all concentrations, but efficiencies of transfer were consistently low in 0 MIC and 1 MIC, with increased activity both above and below 1 MIC. (k-state.edu)
  • Horizontal gene transfer may occur via three main mechanisms: transformation, transduction or conjugation. (msu.edu)
  • Conjugation involves transfer of DNA via sexual pilus and requires cell -to-cell contact. (msu.edu)
  • Genetic interactions among bacteria are mediated by one of the three distinct gene-exchange mechanisms: conjugation, transformation or transduction. (uni-bielefeld.de)
  • Type IV secretion systems (T4SSs) are multisubunit cell-envelope-spanning structures, ancestrally related to bacterial conjugation machines, which transfer proteins and nucleoprotein complexes across membranes. (ox.ac.uk)
  • Trust our stalwart physics color commentator Rob Sheldon to draw the logical conclusion about horizontal gene transfer between plants and insects: If plants and insects can exchange genes (and who knows what else can? (uncommondescent.com)
  • Horizontal gene transfer (HGT) is a fast-track mechanism that allows genetically unrelated organisms to exchange genes for rapid environmental adaptation. (mdpi.com)
  • It has been suggested that lateral gene transfer to humans from bacteria may play a role in cancer. (wikipedia.org)
  • For example, of particular relevance to human health is the lateral transfer of antibiotic resistance and pathogenicity determinants, leading to the emergence of pathogenic lineages. (wikipedia.org)
  • In support of this predicted association, we identified six cases of lateral gene transfer between Megaviridae and oomycetes. (nature.com)
  • Horizontal gene transfer, otherwise called lateral gene transfer, was discovered in 1928 as the result of a detailed set of experiments conducted by Frederick Griffith on bacteria that cause pneumonia. (inhisimage.blog)
  • Phage-mediated transduction - where DNA is transferred from one bacteria to another via a bacteriophage (a virus which affects bacteria). (news-medical.net)
  • Transduction involves transfer of DNA from one bacterium into another via bacteriophages. (msu.edu)
  • Gene transfer via transduction is mediated by bacteriophages which accidentally package donor DNA in their phage head and transfer it to recipient cells. (uni-bielefeld.de)
  • Gene exchange via transduction has been demonstrated under conditions of nutrient depletion and low densities of host cells. (uni-bielefeld.de)
  • Conjugational DNA transfer is driven by the F plasmid unidirectionally from an F + donor cell to an F - recipient cell. (sciencemag.org)
  • Plasmid-mediated HGT of β-lactamase genes to an azide-resistant recipient E. coli strain occurred when the donor and recipient cells were mixed together on stainless steel and in suspension but not on copper surfaces. (asm.org)
  • One plasmid codes for genes that allow the pathogens to create toxins, the other codes for proteins that help it evade the immune system by living inside the white blood cells that kill and digest bacteria. (mpkb.org)
  • The German outbreak strain has the typical plasmid genes of EAEC bacteria as well as shigatoxin genes seen in EHEC (sometimes called STEC, or VTEC) germs. (biofortified.org)
  • a plasmid sharing high similarity with the IncI plasmid pEC_Bactec, including blaCTX-M and blaTEM-1 beta-lactamase (antibiotic resistance) genes [bottom left] and a lot of sequence similar to plasmid pCVM29188_101 from Salmonella entericaKentucky [bottom left]. (biofortified.org)
  • Another plasmid present in the German germ is pEC_Bactec carrying antibiotic resistance gene - a plasmid widely distributed in other gut bacteria like Salmonella . (biofortified.org)
  • Sub-inhibitory concentrations of heavy metals facilitate the horizontal transfer of plasmid-mediated antibiotic resistance genes in water environment. (semanticscholar.org)
  • Brandsch R., Faller W., Schneider K. (1986) Plasmid pAO1 of Arthrobacter oxidans encodes 6-hydroxy-D-nicotine oxidase: cloning and expression of the gene in Escherichia coli. (uni-freiburg.de)
  • Horizontal gene transfer has played a role in developing the global public health crisis of antimicrobial resistance (AMR). (news-medical.net)
  • horizontal gene transfer Explain why the rapid acquisition of antibiotic resistance by bacterial pathogens is associated with growth in biofilms or growth in the presence of bacteriophages. (bartleby.com)
  • Since then, the phenomenon of horizontal gene transfer has been shown to be responsible for widespread transfer among bacterial populations of genes conferring antibiotic resistance, metabolic functions, and virulence determinants. (sciencemag.org)
  • Greenpeace and other activist groups regard HGT as major risk with regard to GMO's that have antibiotic resistance genes. (citizendium.org)
  • Horizontal transfer of transgenic DNA has the potential, among other things, to create new viruses and bacteria that cause diseases and spread drug and antibiotic resistance genes among pathogens. (i-sis.org.uk)
  • A 2010 report found that genes for antibiotic resistance could be transferred by engineering GTAs in the laboratory. (wikipedia.org)
  • Inheritance of drug resistance (and its transfer) between Shigella strains and between Shigella and E. coli strains" (in Japanese). (wikipedia.org)
  • Horizontal gene transfer (HGT) plays a major role in the spread of antibiotic resistance. (nih.gov)
  • This is one way that bacteria can share genes that make them resistant to antibiotics and how antibiotic resistance can spread through a population of bacteria. (yourgenome.org)
  • This medical problem stimulated research in bacterial genetics which revealed that horizontal gene transfer is involved in some of the genetic variations causing resistance to antibiotics. (mdpi.com)
  • Finally, implications for antibiotic usage and the development of resistant infections and persistence of antibiotic resistance genes in populations as a result of horizontal gene transfer in the large intestine will be discussed. (dovepress.com)
  • Bacterial populations susceptible to antibiotics become resistant either through genetic mutation or through horizontal transfer and expression of resistance genes from other strains, either distantly or closely related. (dovepress.com)
  • The human gastrointestinal tract provides an ideal combination of factors for antibiotic resistance genes to arise and spread through bacterial populations. (dovepress.com)
  • The aim of this review is to provide a brief overview of the bacterial processes that facilitate horizontal gene transfer, and to propose how this phenomenon may be taking place in the lower human gastrointestinal tract, specifically the large intestine, intensifying the antibiotic resistance crisis we are currently facing and setting the stage for future resistant infections. (dovepress.com)
  • Our data show that this novel, horizontally gene transferred copper resistance locus is associated with the SCCmec elements of USA300. (findaphd.com)
  • Our hypothesis is that acquisition of copper hyper-resistance via horizontal gene transfer plays a crucial role in the emergence of S. aureus strains, and potentially other pathogenic bacteria, with increased infectivity conferred through their improved resistance to the copper-dependent killing mechanisms of the host's immune cells. (findaphd.com)
  • Multiple genes for heavy metal resistance have been identified in L. monocytogenes. (findaphd.com)
  • 2018 A horizontally gene transferred copper resistance locus confers hyper-resistance to antibacterial copper toxicity and enables survival of community acquired methicillin resistant Staphylococcus aureus USA300 in macrophages. (findaphd.com)
  • Most mobile genetic elements and antibiotic resistance genes are in hotspots, but many hotspots lack recognizable mobile genetic elements and exhibit frequent homologous recombination at flanking core genes. (pasteur.fr)
  • Transconjugants also exhibited the same resistance profile as the donor, suggesting multiple gene transfer. (asm.org)
  • IMPORTANCE Horizontal gene transfer (HGT) conferring resistance to many classes of antimicrobials has resulted in a worldwide epidemic of nosocomial and community infections caused by multidrug-resistant microorganisms, leading to suggestions that we are in effect returning to the preantibiotic era. (asm.org)
  • Horizontal gene transfer between bacteria is a rather general process, leading to the distribution of many traits, such as antibiotic resistance determinants or genes encoding degradative pathways. (asm.org)
  • Antibiotic resistance genes have been used in numerous studies as markers for gene transfer in microcosms mimicking natural ecosystems ( 1 , 15 , 18 , 23 , 30 ). (asm.org)
  • Furthermore, CSP1-E1A attenuated the acquisition of an antibiotic resistance gene and a capsule gene in vivo . (prolekare.cz)
  • Germ HUSEC041 O104:H4 also has new genes for tellurite chemical resistance not possessed by its distant African relative E. coli 55989, and these likely came from EHEC E. coli O157:H7 or its sisters. (biofortified.org)
  • DNA fragments that contain resistance genes from resistant donors can then make previously susceptible bacteria express resistance as coded by these newly acquired resistance genes. (msu.edu)
  • Driven mainly by biosafety research and research into the rapid dissemination of antibiotic resistance, the evaluation of gene flux among bacteria in their natural habitats has become a focus of scientific interest in recent years. (uni-bielefeld.de)
  • To describe the distribution of trimethoprim-sulfamethoxazole resistance genes and the role of horizontal gene transfer and clonal expansion in recent increases of antibiotic resistance rates among uropathogenic Escherichia coli in Europe and Canada. (oup.com)
  • Trimethoprim resistance gene distributions showed no regional dependency ( P = 0.84). (oup.com)
  • The most common trimethoprim resistance gene was dfrA1 , which occurred in 37.9% of dfr containing isolates. (oup.com)
  • Similarly, the sulfamethoxazole resistance gene distributions did not vary significantly by region ( P = 0.20). (oup.com)
  • sul2 , the most common sulfamethoxazole resistance gene, was found in 77.9% of sulfamethoxazole-resistant isolates. (oup.com)
  • Horizontal gene transfer plays a larger role than clonal expansion in the increase of trimethoprim-sulfamethoxazole resistance levels in Europe and Canada. (oup.com)
  • Instead, genetically modified plants, infused with a bacterial gene which conferred resistance to streptomycin, were used. (inhisimage.blog)
  • In this experiment, the normal cultivated tobacco's chloroplasts were modified to include a gene for streptomycin resistance and a fluorescent protein. (inhisimage.blog)
  • The majority of MDR hospital outbreaks are caused by a subset of Kp clones with a high prevalence of acquired antimicrobial resistance (AMR) genes, while the majority of community-acquired invasive infections are caused by hypervirulent clones that rarely harbour acquired AMR genes but have high prevalence of key virulence loci. (edu.au)
  • Horizontal transfer of antibiotic resistance genes in the human gut microbiome. (cdc.gov)
  • A spontaneous recombination within this locus was demonstrated in a bacterial clone containing an antibiotic-resistance gene inserted in flaA. (microbiologyresearch.org)
  • A recombinant was isolated in which the antibiotic-resistance gene had been repositioned into flaB, indicating that genetic information can be exchanged between the two flagellin genes of C. jejuni. (microbiologyresearch.org)
  • The occurrence of recombinational events after the uptake of exogenous DNA by naturally competent bacteria was demonstrated with two mutants containing different antibiotic-resistance markers in their flagellin genes. (microbiologyresearch.org)
  • The goal of this Research Topic is to deepen our understanding of the scope and dynamics of AMR dissemination in different microbiomes, the role of different horizontal gene transfer processes in AMR dissemination, the mobile genetic elements involved in AMR dissemination, the environmental factors/substances that impact the dissemination of AMR, and the cellular regulatory mechanisms that impact AMR dissemination. (frontiersin.org)
  • Horizontal gene transfer processes for AMR dissemination and the regulatory mechanisms for AMR dissemination. (frontiersin.org)
  • The data to date suggest that various mechanisms of horizontal gene transfer with various outcomes and consequences can take place in all natural environments, whether aquatic, terrestrial, or biological, often in biofilms. (asmscience.org)
  • It is likely that this chapter discovers that not only is horizontal gene transfer more widespread than we now can document but that the themes and variations in its mechanisms are much more robust than we can now imagine. (asmscience.org)
  • Other factors favoring spread of resistant infections include antibiotic exposure and subsequent selection followed by the innate ability for gene transfer through a variety of different mechanisms. (dovepress.com)
  • Whereas gene transfer is readily observed in the laboratory, more importantly, field studies have provided direct evidence that all three gene transfer mechanisms also occur in nature. (uni-bielefeld.de)
  • Since his discovery, other mechanisms of horizontal gene transfer have been discovered. (inhisimage.blog)
  • The genes were transferred to the beetles, researchers say, from sea squirts (tunicates) , with whom they have, may we say, not much in common, by microorganisms (symbiont bacterial strains). (uncommondescent.com)
  • Horizontal gene transfer was first observed in 1928, in Frederick Griffith's experiment: showing that virulence was able to pass from virulent to non-virulent strains of Streptococcus pneumoniae, Griffith demonstrated that genetic information can be horizontally transferred between bacteria via a mechanism known as transformation. (wikipedia.org)
  • Strains exhibiting incongruence were then subjected to detailed phylogenetic analysis of horizontal transfer by using multiple housekeeping genes ( gyrB , recA , and pyrH ) and multiple lux genes ( luxCDABEG ). (asm.org)
  • The gene encoding this enzyme has been isolated from a few strains of Pseudomonas spp. (asm.org)
  • Horizontal gene transfer has been found prevalent in prokaryotes but very rare in eukaryote. (pubmedcentralcanada.ca)
  • Although prevalent in prokaryotes, horizontal gene transfer (HGT) is rarer in multicellular eukaryotes. (biomedcentral.com)
  • Recent estimates indicate that, although occurring at a lower frequency than in prokaryotes, HGT in eukaryotes might be less rare than previously thought [ 9 ], and among metazoans there are now several well-documented cases of the horizontal transfer of single genes or small sets of genes from non-metazoan donors. (biomedcentral.com)
  • Highways of gene sharing in prokaryotes. (semanticscholar.org)
  • This last phenomenon is particularly relevant to the present study, as gene transfers are frequent among prokaryotes. (biomedcentral.com)
  • Other "prototype" Nramp genes (intronless, encoding proteins strongly conserved with MntH A and B proteins) identified in invertebrates represent a possible source for transfer of Nramp genes toward opportunistic bacteria. (nih.gov)
  • To gain insight into the frequency of HGT in Vibrionaceae and its possible impact on speciation, we assessed the incidence of interspecies transfer of the lux genes ( luxCDABEG ), which encode proteins involved in luminescence, a distinctive phenotype. (asm.org)
  • Many of the inserted genes in the GM-crops are under the control of the promoter of the Cauliflower mosaic virus (CaMVP35S) and produce insecticidal proteins. (academicjournals.org)
  • These proteins are costly, rendering populations of cooperators vulnerable to exploitation by nonproducing cheaters arising by gene loss or migration. (uzh.ch)
  • Genes encoding proteins that are involved in DNA uptake and transformation, as well as virulence, are upregulated. (prolekare.cz)
  • Methods based on concatenated informational proteins and methods based on character cladistics led to different conclusions regarding the position of Aquificales because this lineage has undergone many horizontal gene transfers. (biomedcentral.com)
  • Most thinking in genetics has focused on vertical transfer, but there is a growing awareness that horizontal gene transfer is a significant phenomenon. (wikipedia.org)
  • Most thinking in genetics has focused upon vertical transfer, but the importance of horizontal gene transfer among single-cell organisms is beginning to be acknowledged. (wikipedia.org)
  • Third, no mechanism of HGT for any of the hundreds of alleged 'foreign genes' they found was either discovered or even suggested. (icr.org)
  • It is quite amazing that bdelloids are able to recruit foreign genes, which were acquired from remarkably diverse sources, to function in the new host," says MBL's Irina Arkhipova. (scienceagogo.com)
  • Using a dated phylogeny, we estimate an average of 12.8 gains versus 2.0 losses of foreign genes per million years. (biomedcentral.com)
  • Foreign genes were mainly enzymes with various annotated functions that include catabolism of complex polysaccharides and stress responses. (biomedcentral.com)
  • Nearly half of foreign genes were acquired before the divergence of bdelloid families over 60 Mya. (biomedcentral.com)
  • Unlike group I introns, at least one of which appears to have been traded within flowering plants ( 16 ), group II introns in plants have been thought to be strictly vertically inherited ( 17 - 19 ), and the only known horizontal transfer of a group II intron in eukaryotes occurred in haptophytes, marine unicellular flagellates ( 20 ). (pnas.org)
  • The acquisition of genes from an organism other than a direct ancestor, which is called horizontal gene transfer (HGT), is well known in bacteria and unicellular eukaryotes [ 1 - 6 ]. (pubmedcentralcanada.ca)
  • However, in recent years, more and more instances of horizontal gene transfer have been reported in multicellular eukaryotes, even in humans [ 7 - 12 ]. (pubmedcentralcanada.ca)
  • The eukaryotes cited above all have "domesticated amidase effectors" ( dae ) genes, all of which are extremely similar to one of the four extant bacterial tae genes. (evmedreview.com)
  • The phylogenetic trees of 2,257 metabolic enzymes were used to make E/HGT assertions in ten groups of unicellular eukaryotes, revealing the sources and metabolic processes of the transferred genes. (biomedcentral.com)
  • Horizontal gene transfer overrides mutation in Escherichia coli colonizing the mammalian gut. (natureindex.com)
  • The objective of this study was to determine the fitness effects of orthologous genes transferred from Salmonella enterica serovar Typhimurium to Escherichia coli to identify the selective barriers using highly precise experimental measurements. (biomedcentral.com)
  • Here we conduct a systematic experimental test of the barriers to HGT by transferring and expressing orthologs from Salmonella enterica serovar Typhimurium to Escherichia coli , and measuring their fitness effects. (biomedcentral.com)
  • This dissertation defines the role of outside factors in conjugative gene transfer, and may provide future insight into better control of AMR. (k-state.edu)
  • Here, we demonstrate transfer of the conjugative transposon Tn 5397 from C. difficile 630 to E. faecalis JH2-2, the first reported gene transfer between these two bacteria. (asm.org)
  • In E. faecalis , the genes responsible have been shown to be carried on conjugative transposon Tn 1549 ( 6 , 20 ). (asm.org)
  • Conjugative gene exchange has been shown to occur under a wide range of environmental conditions. (uni-bielefeld.de)
  • Analyses of 70 seed plant nad1 exons b and c and intron 2 sequences, including representatives of all angiosperm clades, support that this copy originated from a euasterid and was horizontally transferred to Gnetum . (pnas.org)
  • Many bioinformatical and microbiomic analyses have also been performed to elucidate AMR transfer dynamics. (frontiersin.org)
  • Expression analyses of candidate genes of algal and eubacterial origin show that these genes are expressed and developmentally regulated during the life cycle of C. parvum . (biomedcentral.com)
  • Long-branch attraction appears to be misleading parsimony analyses of nuclear small-subunit rDNA data, but model-based methods (maximum likelihood and Bayesian analyses) recover a topology that is congruent with the mitochondrial matR gene tree, thus providing compelling evidence for organismal relationships. (uzh.ch)
  • Analyses revealed a preference for enzymes encoded by genes gained through horizontal and endosymbiotic transfers to be connected in the metabolic network. (biomedcentral.com)
  • Prof. Hans-Hinrich Kaatz from the University of Jena, is reported to have new evidence, as yet unpublished, that genes engineered into transgenic plants have transferred via pollen to bacteria and yeasts living in the gut of bee larvae(1). (i-sis.org.uk)
  • Genes carrying PKS and NRPS domains were identified in clusters on the CDC and evidence supporting the origin of the CDC through horizontal transfer from an unrelated fungus was found. (7thspace.com)
  • Conclusions: We provide evidence supporting the hypothesis that the CDC in A. arborescens was acquired through horizontal transfer, likely from an unrelated fungus. (7thspace.com)
  • Not quite, according to scientists from the Woods Hole Marine Biological Laboratory (MBL), who have uncovered evidence of "massive" horizontal gene transfer in the animal known as the bdelloid rotifer. (scienceagogo.com)
  • Gene transfer, either intracellular from an endosymbiont/donor organelle or horizontal from another organism, can provide evidence of a previous endosymbiotic relationship and/or alter the genetic repertoire of the host organism. (biomedcentral.com)
  • The authors document several lines of evidence to support their conclusion that dae genes in the lineage encompassing ticks and mites are functional and contributing to fitness. (evmedreview.com)
  • Of key importance, the authors show that decreasing expression of the dae2 gene in I. scapularis ticks is associated with higher loads of B. burgdorferi , suggesting, in conjunction with other evidence, that the Dae2 protein is used by the tick to control the load of spirochetes. (evmedreview.com)
  • What is of special note in the transfers of both cysteine synthase and amidase genes is that, unlike in some other cases, the evidence supports the inference that these transferred genes actually benefit their new hosts. (evmedreview.com)
  • Here we provide molecular phylogenetic evidence using DNA sequence data from mitochondrial and nuclear genes for representatives of all genera in Rafflesiales. (uzh.ch)
  • In fact, due to increasing evidence suggesting the importance of the phenomenon in organisms that cause disease, molecular biologists such as Peter Gogarten at the University of Connecticut have described horizontal gene transfer as "a new paradigm for biology. (mpkb.org)
  • Instead, evidence for a large Horizontal Gene Transfer between Aquificales and epsilon-Proteobacteria was found. (biomedcentral.com)
  • Phylogenetic evidence suggests that these globin genes were independently acquired via horizontal gene transfer from some ancestral bacteria. (ijbs.com)
  • Several selective barriers - factors that impact the fitness effect of the transferred gene - have been suggested to impede the likelihood of horizontal transmission, however experimental evidence is scarce. (biomedcentral.com)
  • While horizontal gene transfer has been known in bacteria for a while and is strongly supported by evidence, finding horizontal gene transfer in plants is a more recent development. (inhisimage.blog)
  • We describe the reasons why the newly recognized process of horizontal gene transfer (HGT) forces evolutionists who study classification and microbiology to go beyond the classical Darwinian framework. (springer.com)
  • Horizontal Gene Transfer (or HGT) is the process of an organism acquiring another organism's DNA, usually through absorbing the 'target' organism, resulting in an endosymbiotic relationship. (news-medical.net)
  • Bacteria acquire novel DNA through horizontal gene transfer (HGT), a process that enables an organism to rapidly adapt to changing environmental conditions, provides a competitive edge and potentially alters its relationship with its host. (cdc.gov)
  • In mammals, genes are quite complex, and on average only about 10% of the entire gene sequence actually codes for protein, the rest contains a large diversity of regulatory sequences that determine how the gene is to function and its various types of products. (icr.org)
  • It has also been demonstrated that the CaMV-P35S promoter sequence can convert an adjacent tissue- and organ-specific gene promoter into a globally active promoter. (academicjournals.org)
  • Analysis of the results revealed that: 1) ingested fragments from the CaMV-35S promoter incorporated into blood, liver, and brain tissues of experimental rats, 2) The total mean of transfer of GM target sequences increased significantly by increasing the feeding durations, and 3) The affinity of different transgenic fragments from the ingested GM-diet, to be incorporated into the different tissues of rats varied from one target sequence to the other. (academicjournals.org)
  • This amino acid sequence motif facilitates the process by which a protein is transferred from the intracellular space to the extracellular space. (evmedreview.com)
  • The uncultured brown-pigmented GSB was 99.7% identical in the 16S rRNA gene sequence to its green-pigmented cultured counterpart Chlorobium luteolum DSM 273T. (csic.es)
  • Do orthologous gene phylogenies really support tree-thinking? (wikipedia.org)
  • For instance, the conflicting phylogenies can be the result of events not accounted for by the model, such as unrecognized paralogy due to duplication followed by gene losses. (wikipedia.org)
  • It's not yet clear why there are fewer types of microbes in urban people' guts or why they favor horizontal gene transfer more often. (uncommondescent.com)
  • The team has revealed the likely mechanism by which this gene ended up being expressed in a functionally important and tissue-specific way. (eurekalert.org)
  • This is actually one of the few clearly documented cases of horizontal gene transfer showing that a specific type of parasite-host relationship is the mechanism for the foreign DNA importation to occur and be heritable. (icr.org)
  • A proposed mechanism for this phenomenon was horizontal gene transfer between organisms with ticks as the media [ 13 ]. (pubmedcentralcanada.ca)
  • Natural transformation, one mechanism of horizontal gene transfer, is defined as the process by which bacterial cells successfully take up and incorporate extracellular DNA. (illinois.edu)
  • 2013) found that meal-derived DNA fragments which are large enough to carry complete genes can avoid the total degradation in the gastrointestinal tract, and through an unknown mechanism enter the human circulation system. (academicjournals.org)
  • The most well-known mechanism of horizontal gene transfer is performed by bacteria. (inhisimage.blog)
  • First, they find that the dae genes in ticks and mites and in mollusks have ratios of non-synonymous to synonymous (dN/dS) mutations that are indicative of purifying selection, i.e. selection against codon changes implying a useful function of the current nucleotide sequences. (evmedreview.com)
  • The German outbreak strain is a new strain which has acquired specific gene sequences that have a role in pathogenicity, causing hemorrhagic colitis and hemolytic-uremic syndrome (HUS) . (biofortified.org)
  • The transfer of DNA among pathogens means that once harmless microbes can acquire properties that allow them to cause problems for the host. (mpkb.org)
  • Also it should be noted that other types of pathogens such as viruses can and do engage in horizontal gene transfer. (mpkb.org)
  • Chromosomal genes of the Hfr bacterium can be mobilized and transferred to a recipient. (sciencemag.org)
  • DNA is transferred from the donor to the recipient in single-stranded form and converted to duplex DNA by the synthesis of the complementary strand in the recipient cell. (sciencemag.org)
  • Once the conjugational transfer ceases, double-stranded donor DNA is either circularized (in the case of F′ transfer) or, in the case of Hfr transfer, incorporated into the recipient chromosome by RecA-dependent homologous recombination or degraded by RecBCD exonuclease ( 3 , 6 ). (sciencemag.org)
  • To address these questions, we have developed an experimental system that enables us to distinguish the transferred donor DNA from both donor and recipient DNA, and to visualize DNA transfer and recombination by means of fluorescence microscopy in real time, at the level of individual living cells. (sciencemag.org)
  • We mated Dam methylation-proficient donor (Hfr or F′) cells with methylation-deficient recipient cells, producing the SeqA-YFP (yellow fluorescent protein) fusion protein, which enabled us to specifically and permanently label only the transferred DNA. (sciencemag.org)
  • The results indicate that horizontal transfer of the lux genes in nature is rare and that horizontal acquisition of the lux genes apparently has not contributed to speciation in recipient taxa. (asm.org)
  • Cryptosporidium is the recipient of a large number of transferred genes, many of which are not shared by other apicomplexan parasites. (biomedcentral.com)
  • Analysis of this model indicates that HGT can prevent the operation of Muller's ratchet even when the source of transferred genes is eDNA that comes from dead cells and on average carries more deleterious mutations than the DNA of recipient live cells. (g3journal.org)
  • A GFP-Km (Green fluorescent protein-kanamycin) cassette tagged HGT recipient Acinetobacter strain ADPWH67 with the salicylate hydroxylase gene (salA) disrupted was introduced to slurries containing either sterile or non-sterile soil. (nerc.ac.uk)
  • When the clc genes were transferred into an appropriate recipient bacterium such as Pseudomonas putida F1, a new metabolic pathway for chlorobenzene degradation was formed by complementation which could be selected for by the addition of mono- or 1,4-dichlorobenzene (CB). (asm.org)
  • Under optimized conditions with direct donor-recipient filter matings, very low transfer frequencies were observed (approximately 3.5 × 10 −8 per donor per 24 h). (asm.org)
  • To date, we have little knowledge of the DFE for newly transferred genes, or of the factors that determine those fitness effects, especially following expression in the recipient cell. (biomedcentral.com)
  • We mimicked HGT by transferring genes from S. Typhimurium to an E. coli recipient to determine the DFE and test whether selective barriers - functional category, number of PPI, GC content, codon usage, and dosage sensitivity - affect the likelihood of transfer. (biomedcentral.com)
  • The virion containing these genes then transfers them to a recipient cell. (istudy.pk)
  • As in transformation, once the DNA fragment has been injected, it must be incorporated into the recipient cell's chromosome to preserve the transferred genes. (istudy.pk)
  • The idea was pooh-poohed when first proposed more than 50 years ago, but the advent of drug-resistant bacteria and other discoveries, including the identification of a specialized protein that bacteria use to swap genes, has recently led to wide acceptance of the theory. (scienceagogo.com)
  • The bottom line of it is, long before GM crops existed, we knew that bacteria swap genes like crazy, and rates of gene moment were the, and still are, easy to detect with the right methods. (biofortified.org)
  • Bacteria swap genes in everybody's gut whether there is GM food there or not. (biofortified.org)
  • In a new discovery that increases our understanding of gene transfer, a research team centered at University of Tsukuba has studied a gene in marine invertebrates called ascidians originally came from a common bacterium. (eurekalert.org)
  • 1 The Wolbachia bacterium is able to do this extraordinary feat by targeting the cells of reproductive organs so that the transferred DNA is literally inherited in the host. (icr.org)
  • and (iv) a strain of the luminous bacterium Photobacterium mandapamensis was found to be merodiploid for the lux genes, and the second set of lux genes was closely related to the lux genes of the lux - rib 2 operon of P. leiognathi . (asm.org)
  • Because of their complementary approaches-and often non-overlapping sets of HGT candidates-combining predictions from parametric and phylogenetic methods can yield a more comprehensive set of HGT candidate genes. (wikipedia.org)
  • T4SSs are usually encoded by multiple genes organized into a single functional unit. (ox.ac.uk)
  • This gene encodes a protein that helps form an external protective coating, the loss of which leads to a lack of cellulose production and has adverse effects on these organisms. (eurekalert.org)
  • In contrast, dosage sensitivity, gene length, and the intrinsic protein disorder significantly impact the likelihood of a successful horizontal transfer. (biomedcentral.com)
  • Menéndez C., Igloi G., Henninger H., Brandsch R. (1995) A pAO1-encoded molybdopterin cofactor gene (moaA) of Arthrobacter nicotinovorans: characterization and site-directed mutagenesis of the encoded protein. (uni-freiburg.de)
  • Microorganisms appear to be most affected by HGT, but even in microbes only about 2% of core genes are transferred laterally. (citizendium.org)
  • Professor Bansal is leading a research project, recently funded by the NSF, to develop new computational methods for studying Horizontal Gene Transfer (HGT) in microbes. (uconn.edu)
  • High levels of endosymbiotic gene transfer (EGT) accompanied the establishment of plastids and mitochondria, and more recent events have allowed further acquisition of bacterial genes. (biomedcentral.com)
  • Molecular clock dating, using calibrations provided by gnetalean macrofossils, suggests an age of 5 to 2 million years for the Asian clade that received the horizontal transfer. (pnas.org)
  • RESULTS: Our model predicts that differential gene mobility drives intragenomic variation in investment in cooperative traits. (uzh.ch)
  • The fungus is almost always found among and within poplar trees, and in an effort to understand its influence on the plant, a team of scientists studied what happens to the tree's physical traits and gene expression when the fungus is present. (doe.gov)
  • Mihasan M. and Brandsch R. (2013) pAO1 of Arthrobacter nicotinovorans and the spread of catabolic traits by horizontal gene transfer in Gram-positive soil bacteria. (uni-freiburg.de)
  • The genes for bacterial light production, luxCDABEG , are present in bacteria as a conserved, contiguous, and coordinately expressed set of genes, the lux operon. (asm.org)
  • This led us to suggest that the operon might have been acquired by the bacilli through horizontal gene transfer (HGT). (pasteur.fr)
  • Members of the PS-clade of cyanobacteria contain a proteobacterial form 1A RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) that was acquired by horizontal gene transfer (HGT) of a carboxysomal operon. (biomedcentral.com)
  • Gene content and order in the carboxysomal operon correlates well with the RubisCO phylogeny demonstrating that the complete carboxysomal operon was acquired by the common ancestor of the Paulinella chromatophore and the PS-clade through HGT. (biomedcentral.com)
  • The carboxysomal operon shows a significantly elevated AT content in Paulinella , which in the rbcL gene is confined to third codon positions. (biomedcentral.com)
  • If genes encoding metabolic enzymes are horizontally transferred and are advantageous, they are likely to become fixed. (biomedcentral.com)
  • A third parent is the donor of the shigatoxin gene (stx2), which is likely to be the common food poisoning germ E.coli O157:H7 EHEC strain, which itself carries the gene stx2 within a mobile virus cassette that appears as an identical DNA that is in a somewhat shortened version in the German germ. (biofortified.org)
  • In addition, this approach could potentially link specific metabolite changes with corresponding catabolic genes. (nerc.ac.uk)
  • Identification of horizontal gene transfer and recombination of PsaA gene in streptococcus mitis group. (semanticscholar.org)
  • The subunit of the flagellar filament of C. jejuni is encoded by two tandem genes, flaA and flaB, which are highly similar and therefore subject to recombination. (microbiologyresearch.org)
  • Typically, this process affects genes involved in DNA repair and recombination in early association stages, further increasing the mutation rate and preventing genetic exchange by homologous recombination. (nature.com)