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).
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
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: ...
What if, for example, the gene modification ends up altering a mosquitos behavior-making it more aggressive, or changing its host preference. (In the case of Aedes aegypti, which already prefers humans, a change in host preference might not be so bad.) Or what if the mosquitoes end up transferring their altered genes horizontally-to other non-target species, rather than just to their own offspring? This is more of a problem with genetically modified bacteria, which has also been proposed to fight Zika, but Durvasula says unplanned horizontal gene transfer is unlikely to create any issues among Aedes aegypti that are genetically modified to be sterile.. You can start to fantasize about every possible fate of that gene, but its impossible to test all of that in a lab, he said. And once youve released a trait into a population, there cannot be a recall. This is what scares people. People get creeped out by these things.. That fear is standing in the way of engineering Aedes aegypti into ...
In article ,Co2Isu.n4r at, lamoran at 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
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 ...
Poptsova M (2009). "Testing Phylogenetic Methods to Identify Horizontal Gene Transfer". Horizontal Gene Transfer. Methods in ... Index of evolutionary biology articles Horizontal gene transfer Horizontal gene transfer in evolution Phylogenetic tree ... Horizontal or lateral gene transfer (HGT or LGT) is the transmission of portions of genomic DNA between organisms through a ... Horizontal gene transfer was first observed in 1928, in Frederick Griffith's experiment: showing that virulence was able to ...
... which states that horizontal gene transfer is constantly occurring in operational genes. Plant-fungus horizontal gene transfer ... Horizontal gene transfer is universal in fungi, viruses, bacteria, and other eukaryotes. Horizontal gene transfer research ... and gene transfer between mitochondrial genes. Horizontal gene transfer could bypass eukaryotic barrier features like linear ... Sterigmatocystin gene transfer has been observed with Podospora anserina and Aspergillus. Horizontal gene transfer in ...
Horizontal gene transfer Inferring horizontal gene transfer Woese C, et al. (1990). "Towards a natural system of organisms: ... This movement of genes can occur through horizontal gene transfer (HGT), scrambling the information on which biologists relied ... This lateral gene transfer occurred also beyond the Darwinian threshold, after heredity or vertical gene transfer was ... Horizontal Gene Transfer, Oklahoma State Doolittle, WF (2000). "Uprooting the tree of life". Sci Am. 282 (2): 90-5. Bibcode: ...
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 ... "Horizontal gene transfer". Journal of Genetics. 75 (2): 219-232. doi:10.1007/bf02931763. S2CID 5989957. Staff (16 July 2021). " ... It is theorized that when this S. aureus strain that had acquired the mecA gene was introduced into hospitals, it came into ...
... horizontal gene transfer can occur again, and the cell can 'try again' to have successful transfer of genes to the nucleus. ... Ford Doolittle proposed a gene transfer ratchet mechanism to explain the unidirectional transfer of genes from the organelle ... Syvanen, Michael; Kado, Clarence I. (30 January 2002). Horizontal Gene Transfer. Academic Press. p. 405. ISBN 978-0126801262. ... Ford Doolittle, W (1998-12-01). "You are what you eat: a gene transfer ratchet could account for bacterial genes in eukaryotic ...
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 ...
A wide variety of comparative analyses were used to determine that horizontal gene transfer (HGT) influenced the evolution of ... Siefert, Janet (2009-02-01). "Defining the Mobilome". Horizontal Gene Transfer. Methods in Molecular Biology (Clifton, N.J.). ... The first form of gene transfer used by Lactobacillus is transformation. This includes the uptake of naked DNA by a recipient ... Bacun-Druzina, Visnja; Mrvčić, Jasna; Ana, Butorac; Gjuracic, Kresimir (2009-09-01). "The influence of gene transfer on the ...
Most likely, these genes were acquired through horizontal gene transfer from viral hosts. Organisms are complex chemical ... Horizontal gene transfer makes it more difficult to study the last universal ancestor. However, the universal use of the same ... Gogarten P. "Horizontal Gene Transfer - A New Paradigm for Biology". Retrieved 20 August 2011. Gibson DG, ... Melcher U (1987). "Horizontal Gene Transfer". Molecular Genetics. Oklahoma State. Archived from the original on 20 February ...
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 ...
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. ...
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 ...
2012). Horizontal gene transfer in microorganisms. Norfolk, UK: Caister Academic Press. ISBN 978-1-908230-10-2. Busse, Hans- ... "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 ...
Memetics Horizontal gene transfer Wolfram, Walt; Schilling-Estes, Natalie (2003), "Dialectology and Linguistic Diffusion" (PDF ...
Horizontal gene transfer refers to the transfer of genetic material through a mechanism other than reproduction. This mechanism ... Gene dosage Gene expression Gene family Gene nomenclature Gene patent Gene pool Gene redundancy Genetic algorithm Haplotype ... There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first ... via horizontal gene transfer. Whereas the chromosomes of prokaryotes are relatively gene-dense, those of eukaryotes often ...
... states that the high levels of horizontal gene transfer, rapid mutation rates in viral genomes, and lack of universal gene ... Archaea show high levels of horizontal gene transfer between lineages. Some researchers suggest that individuals can be grouped ... Sota M, Top EM (2008). "Horizontal Gene Transfer Mediated by Plasmids". Plasmids: Current Research and Future Trends. Caister ... from horizontal gene transfer. The standard hypothesis states that the ancestor of the eukaryotes diverged early from the ...
Horizontal Gene Transfer:Genomes in Flux. Methods in Molecular Biology. Vol. 532. Humana Press. pp. 181-191. doi:10.1007/978-1- ... "Genome acquisition in horizontal gene transfer: symbiogenesis and macromolecular sequence analysis". In Gogarten, Maria Boekels ... The power of phylogenetic approaches to detect horizontally transferred genes. Evolutionary Biology. Vol. 7. pp. 45-78. doi: ... In 1997 she transferred to the Department of Geosciences at Amherst to become Distinguished Professor of Geosciences "with ...
Gene. 5 (3): 197-206. doi:10.1016/0378-1119(79)90078-7. PMID 467979. Juhas M (February 2015). "Horizontal gene transfer in ... allowing horizontal gene transfer. Plasmids often carry genes that are responsible for bacterial antibiotic resistance; as ... Harrison E, Brockhurst MA (June 2012). "Plasmid-mediated horizontal gene transfer is a coevolutionary process" (PDF). Trends in ... Siefert JL (2009). "Defining the mobilome". In Gogarten MB, Gogarten JP, Olendzenski LC (eds.). Horizontal Gene Transfer: ...
Boto, Luis (2010). "Horizontal Gene Transfer in Evolution: Facts and Challenges". Proc Biol Sci. 277 (1683): 819-827. doi: ... Kurland, CG; Canback, B; Berg, OG (2003). "Horizontal Gene Transfer: A Critical View". Proc Natl Acad Sci U S A. 100 (17): 9658 ... In Reticulate Evolution: Symbiogenesis, Lateral Gene Transfer, Hybridization and Infectious Heredity. Springer. pp. 1-40. ISBN ... Newman, Stuart A.; Müller, Gerd B. (2006-01-06), "Genes and Form", Genes in Development, Duke University Press, pp. 38-73, doi: ...
Babić A.; Linder AB.; Vulić M.; Stewart AJ; Radman, M. (2008). "Direct visualization of horizontal gene transfer". Science. 319 ... Radman developed a methodology which enables direct visualization of horizontal gene transfer. Antoine Lacassagne Award (1979 ...
He has also identified several cases of horizontal gene transfer. Scholia has an author profile for Patrick J. Keeling. "Two ... Keeling, Patrick J.; Palmer, Jeffrey D. (2008). "Horizontal gene transfer in eukaryotic evolution". Nature Reviews Genetics. 9 ... "A Tertiary Plastid Uses Genes from Two Endosymbionts". Journal of Molecular Biology. 357 (5): 1373-1382. doi:10.1016/j.jmb. ... "Characterization of a Divergent Sec61β Gene in Microsporidia". Journal of Molecular Biology. 359 (5): 1196-1202. doi:10.1016/j. ...
... having been obtained through horizontal gene transfer from bacteria, fungi and plants. How and why horizontal gene transfer ... Gladyshev, Eugene A.; Meselson, Matthew; Arkhipova, Irina R. (2008-05-30). "Massive horizontal gene transfer in bdelloid ... Large-scale horizontal transfer of bacterial, plant and fungal genes into bdelloid rotifers has been documented, and may ... it has been shown that they undergo a potentially unique genetic process where horizontal gene transfer occurs[citation needed ...
Gene transfer between species includes the formation of hybrid organisms and horizontal gene transfer. Migration into or out of ... as when one bacteria acquires resistance genes it can rapidly transfer them to other species. Horizontal transfer of genes from ... Horizontal gene transfer is the transfer of genetic material from one organism to another organism that is not its offspring; ... allowing transfer of genes even across biological domains. Large-scale gene transfer has also occurred between the ancestors of ...
Gogarten, J. Peter; Townsend, Jeffrey P. (2005). "Horizontal gene transfer, genome innovation and evolution". Nature Reviews ... On top in the middle is visualized a horizontal event, such as hybridization between members of different classes, leading to a ... Vertical axis is time, horizontal axis may be richness, morphological diversity, some other population measure or even scaled ... thereby representing horizontal evolutionary events. Trees as graph theoretical constructs are composed of vertices (nodes) ...
Gene transfer between species includes the formation of hybrid organisms and horizontal gene transfer. Horizontal gene transfer ... as when one bacteria acquires resistance genes it can rapidly transfer them to other species. Horizontal transfer of genes from ... Due to horizontal gene transfer, this "tree of life" may be more complicated than a simple branching tree, since some genes ... Gladyshev, Eugene A.; Meselson, Matthew; Arkhipova, Irina R. (30 May 2008). "Massive Horizontal Gene Transfer in Bdelloid ...
Gene transfer between species includes the formation of hybrid organisms and horizontal gene transfer. Population genetic ... as when one bacteria acquires resistance genes it can rapidly transfer them to other species. Horizontal transfer of genes from ... Horizontal gene transfer is the transfer of genetic material from one organism to another organism that is not its offspring; ... allowing transfer of genes even across biological domains. Large-scale gene transfer has also occurred between the ancestors of ...
... but the gene for NDM-1 can spread from one strain of bacteria to another by horizontal gene transfer. Carbapenems are a class ... which will allow the gene to be readily transferred between different strains of bacteria by horizontal gene transfer. All the ... The gene for NDM-1 is one member of a large gene family that encodes beta-lactamase enzymes called carbapenemases. Bacteria ... "Characterization of a new metallo-beta-lactamase gene, bla(NDM-1), and a novel erythromycin esterase gene carried on a unique ...
Park, Gene (September 17, 2020). "PlayStation CEO Jim Ryan says more PlayStation 5 units will be available than PS4s in 2013". ... In April 2021, Sony released a new software update through which users can transfer their downloaded PS5 game to an external ... The lower portion of the Control Center contains a customizable horizontal row of icons, including notifications, status ... Players can synchronize their saved game files through cloud storage or transfer them using a USB storage device so no progress ...
In 2012, to guarantee a high level of conservation and access, as well as to transfer the considerable financial burden of ... As his son John Lloyd Wright wrote: William Eugene Drummond, Francis Barry Byrne, Walter Burley Griffin, Albert Chase McArthur ... They were overruled by Wright, but the contractor secretly added extra steel to the horizontal concrete elements. In 1994, ... In his Prairie School days, Wright's office was populated by many talented architects, including William Eugene Drummond, John ...
... and have probably been replaced with genes from other microbes through horizontal gene transfer. Some of the genes the nucleus ... Some of the genes have been lost, others have migrated to the amoeba's nucleus through endosymbiotic gene transfer. Other genes ... which were probably integrated into their genome through horizontal gene transfer from its cyanobacterial prey. Similar genes ... "The ancestor of the Paulinella chromatophore obtained a carboxysomal operon by horizontal gene transfer from a Nitrococcus-like ...
The ceremonies for the transfer of power were held a day earlier in Karachi, at the time the capital of the new state of ... Gene Diversity in Some Muslim Populations of North India Human Biology - Volume 77, Number 3, June 2005, pp. 343-353 - Wayne ... all spaces were spanned by means of horizontal beams, the Islamic architecture was arcuate, i.e. an arch or dome was adopted as ... However, some Indian Muslims were found with detectable, traceable, minor to some levels of gene flow from outside, primarily ...
9686 The silver dapple gene is not a graying gene. It is a dilution gene which acts only on black pigment. "Coat Colors of ... "2018 Transfer Rules". Palomino Horse Breeders of America. Retrieved February 18, 2020. "Horse coat color tests" from the UC ... have a tan body with a darker mane and tail plus primitive markings such as a dorsal stripe down the spine and horizontal ... Cream gene Dilution gene Equine coat color Equine coat color genetics Palomino rabbit Pierce, Benjamin A (2008). Genetics: A ...
It had a square body and featured a low-mounted horizontal stabilizer flush with the main wing, the only member of the Mohajer ... Eugene Miasnikov (6 December 2004). "Terrorists Develop Unmanned Aerial Vehicles". Center for Arms Control, Energy and ... One operator controls the UAV's camera and the ground control station's directional antenna for real time video transfer. The ... and a horizontal tail. The belly skids are non-retractable, but can compress on landing to reduce shock. Apart from the skids, ...
SINEs can be transferred between individuals or species via horizontal transfer through a viral vector. SINEs are known to ... They seem to play a particularly important role in the regulation of gene expression and the creation of RNA genes. This ... The regions coding miRNA can be independent RNA-genes often being anti-sense to neighboring protein-coding genes, or can be ... The co-localization of microRNA and protein-coding genes provides a mechanistic foundation by which microRNA regulates gene- ...
Y' Turret's shell-transfer ring jammed at salvo 20, due to a shell sliding out of its tray due to the motion of the ship as the ... The horizontal protection over the magazines consisted of three layers with a total thickness of 9.13 in (232 mm); the weather ... ISBN 978-1-84603-388-9. Rasor, Eugene L. (1998). The China-Burma-India Campaign, 1931-1945: Historiography and Annotated ... In order to bring ammunition into the turret at any degree of train, the design included a transfer ring between the magazine ...
The board included Eugene Lindsay Bishop and Kenneth F. Maxcy. In addition, Carey announced that dumping at Edgemere would end ... 6. Plan Is to Speed Up Transfer of Mail" (PDF). Wave of Long Island. p. 1. Retrieved August 10, 2018. " ... and installing a horizontal-wire grid over the landfill to discourage birds from landing on it. This was in addition to the ...
The gene for aerolysin have been shown to undergo Horizontal gene transfer from prokaryotes to eukaryotes" (PDF). Nature ... Howard SP, Garland WJ, Green MJ, Buckley JT (June 1987). "Nucleotide sequence of the gene for the hole-forming toxin aerolysin ...
Some species use external spermatophores for sperm transfer. In Hormogaster samnitica and Hormogaster elisae transcriptome DNA ... 1] Novo M, Riesgo A, Fernández-Guerra A, Giribet G (2013). "Pheromone evolution, reproductive genes, and comparative ... creating horizontal burrows in upper 10-30 cm of soil (endogeic); and (3) worms that construct permanent deep vertical burrows ... via a tube which forms a series of loops entwined by blood capillaries that also transfer waste into the tubule of the ...
Although horizontal gene transfer is the most common way for bacterial growth to occur, there is evidence that vertical gene ... Transmission is mainly via horizontal gene transfer, but vertical transmission can also occur. BCWD may be referred to by a ... Flavobacterium psychrophilum is a bacterium that reproduces and multiples via horizontal gene transfer. ... transfer may also play a role in transmission. Quaternary ammonium compounds can be added to the water of infected adult fish ...
... high number of genes associated with oligosaccharide metabolism is a result of gene duplication and horizontal gene transfer, ... This occurred as the three species had extensive DNA similarity including a 16S rRNA gene sequence similarity greater than 97 ... Currently, strain identification is done through polymerase chain reaction (PCR) on the subtly different 16S rRNA gene ... Cancer Gene Therapy. 7 (2): 269-274. doi:10.1038/sj.cgt.7700122. PMID 10770636. Sakata, Shinji; Kitahara, Maki; Sakamoto, ...
Racers don't use a baton, but instead transfer via touch of the body in the exchange zone. The incoming racer cannot use their ... A 1999 study found for people in the F2, F3 and F4 classes in the discus, elbow flexion and shoulder horizontal abduction are ... Broekhoff, Jan (1986-06-01). The 1984 Olympic Scientific Congress proceedings: Eugene, Ore., 19-26 July 1984 : (also: OSC ... A 1999 study found for people in the F2, F3 and F4 classes in the discus, elbow flexion and shoulder horizontal abduction are ...
Horizontal transfer has been experimentally induced and appears to have been proven in Focs past and so seems the more likely ... Concordant evidence from nuclear and mitochondrial gene genealogies". Proceedings of the National Academy of Sciences. 95 (5): ... by the disequilibrium study also failed to reject recombination however this could be consistent with horizontal transfer. ...
... evidence for horizontal gene transfer". Proceedings of the National Academy of Sciences of the United States of America. 102 ( ... Rosette C, Karin M (March 1995). "Cytoskeletal control of gene expression: depolymerization of microtubules activates NF-kappa ... Genes & Development. 15 (10): 1167-81. doi:10.1101/gad.894001. PMID 11358861. Forth S, Kapoor TM (June 2017). "The mechanics of ... which has provided information on the differential expression of the genes depending on the presence of these factors. This ...
Furthermore, comparative genomics indicates horizontal gene transfer between Beggiatoa and Cyanobacteria of storage, metabolic ... Pasulka A, Hu SK, Countway PD, Coyne KJ, Cary SC, Heidelberg KB, Caron DA (July 2019). "SSU-rRNA Gene Sequencing Survey of ... ISBN 978-0-387-95592-6. Mukhopadhyaya PN, Deb C, Lahiri C, Roy P (August 2000). "A soxA gene, encoding a diheme cytochrome c, ... The average filament length achieved through this process is also result of gene-environment interactions as, for instance, the ...
The deal is a horizontal merger (i.e., in which a company buys up a corporation that produces the same goods and products) as ... Maddaus, Gene (November 22, 2019). "Justice Department Goes to Court to Lift Paramount Consent Decrees". Variety. Archived from ... and that they would transfer their national ad sales for their first-run and off-network shows by the company to CBS Television ... Horizontal mergers are more likely to be disapproved than vertical mergers, as they affect a more tangible reduction in ...
Discovered in 1946 by Joshua Lederberg and Edward Tatum, conjugation is a mechanism of horizontal gene transfer as are ... Bacterial conjugation is the transfer of genetic material (plasmid) between bacterial cells by direct cell-to-cell contact or ... Bacterial genetics is the subfield of genetics devoted to the study of bacterial genes. Bacterial genetics are subtly different ...
A point of criticism of GMOs is the use of genetic engineering techniques to imprecisely perform horizontal gene transfer. For ...
... the influence of rate heterogeneity and horizontal gene transfer". BMC Evolutionary Biology. 4 (1): 40. doi:10.1186/1471-2148-4 ...
... revealed that its environmental adaptations likely originated from horizontal gene transfer from thermoacidophilic archaea and ... "Gene transfer from bacteria and archaea facilitated evolution of an extremophilic eukaryote". Science. 339 (6124): 1207-10. ...
Horizontal gene transfer (HGT) has been thought to have occurred between fungal ruminants, like A. robustus, and bacteria that ... Through this gene transfer, it is thought that it has adopted some of the biosynthetic genes the fungus uses to break down ... Specifically, the gene within the fungus that produces xylanase has been identified in the lab for potential use in food ... The introduction of this gene into flour used in baking has been shown to improve the appeal of bread by making the it softer ...
... it may be involved in horizontal gene transfer; it may provide nutrients; and it may act as a buffer to recruit or titrate ions ... The purified DNA is then amplified for a specific gene target so it can be sequenced and categorised based on its sequence. ... Recent investigations revealed that DNA preserved in marine sediments is characterized by a large number of highly diverse gene ... Finkel SE, Kolter R (November 2001). "DNA as a nutrient: novel role for bacterial competence gene homologs". Journal of ...
"Horizontal gene transfer in Histophilus somni and its role in the evolution of pathogenic strain 2336, as determined by ... while allowing a better understanding of the role of horizontal gene transfer in the evolution of these strains Plasmid-borne ... Genomic studies related to this bacteria have enabled scientist to pin point antibiotic resistance genes. Histophilus somni is ... 2,263,857 base pairs with 1,980 protein coding genes) and preputial strain 129Pt (2,007,700 base pairs with 1,792 protein ...
On another level, one can map the horizontal gene transfer processes, by determining the phylogeny of the individual genes ... Horizontal gene transfer is the mobility of genetic info between different organisms that can have immediate or delayed effects ... "Horizontal Gene Transfer: From Evolutionary Flexibility to Disease Progression". Frontiers in Cell and Developmental Biology. 8 ... There are several processes in nature which can cause horizontal gene transfer. This does typically not directly interfere with ...
1922 Radial arm saw A radial arm saw has a circular saw mounted on a sliding horizontal arm. In addition to making length cuts ... The origin of strobe lighting dates to 1931, when Harold Eugene Edgerton invented a flashing lamp to make an improved ... to transfer pressure from the controlling unit, which is usually near the operator of the vehicle, to the actual brake ... It is a base-10 logarithmic scale obtained by calculating the logarithm of the combined horizontal amplitude of the largest ...
Mutation of genes may disrupt the normal process and results in abnormity of breast. The protein tyrosine receptor type F gene ... transfer dynamic muscle and reposition nipple areola region. The treatment of nipple areola relocation provides space for ... which often been undiagnosed because the clinical feature is only breast asymmetry and a horizontal anterior axillary fold, ... The most common case is the mutation of EDA1 gene which is in X chromosome, and this mutation results in X-linked form ...
De Mar, Robert Eugene (1966). The phylogenetic and functional implications of the armor of the Dissorophidae. Vol. 16. [Chicago ... Gerrothorax is thought to have lifted its skull to around 50° above horizontal through the flexing of the atlanto-occipital ... which could transfer carbon dioxide to the bones to neutralize acidic build up in the blood (early semiaquatic tetrapods would ...
Horizontal gene transfer (HGT) is a form of genic inheritance that occurs between individuals in a population or between ... Horizontal gene transfer (HGT) is a form of genic inheritance that occurs between individuals in a population or between ... The first is to quantify intrinsic selection acting on newly transferred genes, by experimentally transferring and expressing ... work will provide a systematic analysis of the roles of different factors in affecting the outcomes of horizontal gene transfer ...
horizontal gene transfer News Scientific American: Horizontal gene transfer more common than thought. Posted on July 2, 2014. ... Bacterial gene helps coffee beetle get its fix). But such events, known as horizontal gene transfer, were thought to be rare. ... by the shape of the laterally transferred gene. In fact, that is precisely how laterally transferred genes are identified, ... Excerpt: There is also compelling evidence that not only may mutations be non-random but horizontal gene transfer too need not ...
Horizontal gene transfer (HGT) plays an important role in the adaptation of lineages to changing environments. The extent of ... Extensive horizontal gene transfers between plant pathogenic fungi. Overview of attention for article published in BMC Biology ... being putatively transferred between Magnaporthales and Colletotrichum. These gene transfers are often physically linked in the ... Such episodes of transfer typically involve hundreds of genes and are thought to be possible only in the case of endosymbiosis ...
... Emmelien Vancaester, Thomas Depuydt (UGent ... Genetics, Ecology, Evolution, Behavior and Systematics, Molecular Biology, horizontal gene transfer, diatoms, vitamin B12, ... "Comprehensive and Functional Analysis of Horizontal Gene Transfer Events in Diatoms." MOLECULAR BIOLOGY AND EVOLUTION, vol. 37 ... "Comprehensive and Functional Analysis of Horizontal Gene Transfer Events in Diatoms." MOLECULAR BIOLOGY AND EVOLUTION 37 (11): ...
... a process called Horizontal Gene Transfer (HGT), has a major impact on bacterial evolution. In an ongoing project at Harvey ... Here, we leverage genes relative position to make a better measurement of gene similarity. These improved similarity ... This thesis builds on that project, by improving our ability to identify gene families --- groups of genes in different strains ... Previously, similarity was measured only by comparing two genes DNA sequences, ignoring their positions on the organisms DNA ...
Kin discrimination promotes horizontal gene transfer between unrelated strains in Bacillus subtilis. In: Nature communications ... Kin discrimination promotes horizontal gene transfer between unrelated strains in Bacillus subtilis. Nature communications. ... Kin discrimination promotes horizontal gene transfer between unrelated strains in Bacillus subtilis. / Stefanic, Polonca; ... Kin discrimination promotes horizontal gene transfer between unrelated strains in Bacillus subtilis. ...
Horizontal gene transfer (HGT) is an important mechanism by which bacteria recombine and acquire novel genes and functions. ... Key words: horizontal or lateral gene transfer / stochasticity / selection / population dynamics / survival / transgenes / ... Modeling suggests frequency estimates are not informative for predicting the long-term effect of horizontal gene transfer in ... Phylogeny of chitinases and its implications for estimating horizontal gene transfer from chitinase-transgenic silver birch ( ...
The TWiM team marvels over the finding of a completely nitrifying Nitrospira, and horizontal gene transfer from Wolbachia into ... and Xindan about their careers and their work on horizontal gene transfer, quorum sensing, and chromosome organization in ... and nested symbiosis facilitated by horizontal gene transfer from bacteria to insect. ... then divulge the transfer of interbacterial antagonism genes to eukaryotes, where they may function in innate defense. ...
Sagi Snir , Horizontal Gene Transfer Phylogenetics: A Random Walk Approach , CGSI 2022. ... Sagi Snir , Horizontal Gene Transfer Phylogenetics: A Random Walk Approach , CGSI 2022 ...
Toxicity, allergies, and possible horizontal gene transfer (HGT) to the environment or to other species have been associated ... Horizontal Gene Transfer (HGT). Fred Griffith described the mechanism of transferring genetic material from heat-killed ... Although the probability of horizontal gene transfer is quite low, the use of genes that confer antibiotic resistance as ... Horizontal gene transfer of the algal nuclear gene psbO to the photosynthetic sea slug Elysia chlorotica. Proc. Natl. Acad. Sci ...
But horizontal gene transfers making evolution superfluous is the least of its problems. For in order for the evolutionary ... What, then, is the quantitation of the design of Horizontal Gene Transfer?. Provide equations, so we can check your math.. ... Horizontal Gene Transfer and the Evolution of Evolution: You Cant Make This Up ... So we must believe that evolution, sans horizontal gene transfer, somehow happened upon such a facility which then allowed for ...
What are "commensal bacteria" and where are they found? Briefly explain how horizontal gene transfer could lead to antibiotic ... Review the sections on natural selection, antibiotics, and bacterial horizontal gene transfer in your text. • Perform web ... Watch this 10-minute video on MRSA to learn about how resistance genes can be transferred between bacteria. ... bacterial horizontal gene transfer. Published by admin at May 6, 2021. Categories *Cheap Nursing Papers ...
Posts about horizontal gene transfer written by eliesbik ... Tag Archives: horizontal gene transfer Non-human microbiome ... horizontal gene transfer, Peer Review, preterm birth, Publons, rumen, seminar, sheep, soil, water, yoghurt , Leave a comment ... horizontal gene transfer, Ion-torrent, jackal, methanotrophs, peat bog lakes, root bacteria, soil, tundra, water , Leave a ... we have determined gene distributions and gene phylogenies for the 267,568 protein-coding genes of 134 sequenced archaeal ...
Dutta C, Pan A. Horizontal gene transfer and bacterial diversity. Journal of Biosciences. 2002 Feb; 27(1 Suppl 1): 27-33. ... Through the introduction of novel physiological traits from distantly related organisms, horizontal gene transfer often causes ... amount of genetic information is inserted into or deleted from such genomes through the process of horizontal transfer. ...
Horizontal gene transfer by the parasitic plant striga hermonthica. Satoko Yoshida, Shinichiro Maruyama, Hisayoshi Nozaki, Ken ... Yoshida S, Maruyama S, Nozaki H, Shirasu K. Horizontal gene transfer by the parasitic plant striga hermonthica. Science. 2010 ... Horizontal gene transfer by the parasitic plant striga hermonthica. In: Science. 2010 ; Vol. 328, No. 5982. pp. 1128. ... Horizontal gene transfer by the parasitic plant striga hermonthica. / Yoshida, Satoko; Maruyama, Shinichiro; Nozaki, Hisayoshi ...
The mitogenomes are 265,696 and 275,898 bp in length and contain a typical set of mitochondrial genes, with 10 missing or ... Each mitogenome also possesses a structurally unusual ccmFC gene, which exhibits splitting of one exon and a shift to trans- ... A few candidate regions for plastome-to-mitogenome transfer were identified, with one suggestive of possible HGT. The lack of ... Based on phylogenetic analysis of mitochondrial genes from across angiosperms and similarity-based searches, there is little to ...
Life sciences/Genetics/Molecular genetics/Epigenetics/Gene transfer/Horizontal gene transfer * /Life sciences/Genetics/ ... Mechanism of Successful Horizontal Gene Transfer between Divergent Organisms Explained (2 of 2) (IMAGE) University of Tsukuba ... Mechanism of successful horizontal gene transfer between divergent organisms explained. University of Tsukuba ... Mechanism of Successful Horizontal Gene Transfer between Divergent Organisms Explained (1 of 2) ...
Horizontal gene transfer (HGT), the movement of genetic material across branches of the tree of life, is well established in ... Horizontal Gene Transfer in Eukaryotes: Not if, but How Much?. *Julia Van Etten, ... SWEET Genes for Disease Resistance in Plants. *Pushpendra K. Gupta. Sugar transporters called SWEETs are utilized by plants for ... This is explained in part by relatively compact prokaryote genomes that facilitate assembly and gene prediction, resulting in ...
Chemtrails and Horizontal Gene Transfer - The GMO Connection. There are a number of highly crucial points this article makes ... heat shock and pollutants such as heavy metals can favor horizontal gene transfer; and the presence of antibiotics can increase ... Consider: these foods are the product of genetic engineering, of what scientists call "horizontal gene transfer" from one ... Therefore, more and stronger antibiotics are being used, which increases - you guessed it once again - horizontal gene transfer ...
One of the key concepts you explore is "horizontal gene transfer." Give us a laymans explanation of what this is, with ... But horizontal gene transfer has revealed that nature does sometimes make leaps, whereby huge lumps of DNA can appear in an ... Horizontal gene transfer is essentially sideways heredity. Its the passage of genetic material sideways, from one creature ... Its not just incremental mutation, but horizontal gene transfer, bringing entirely new packages of DNA into genomes. ...
p. 1468) found that numerous genes in the mitochondrion were acquired by horizontal gene transfer from other plants, including ... Many of these horizontal transfers were large, including acquisition of entire mitochondrial genomes from three green algae and ... Widespread horizontal transfer of mitochondrial genes in flowering plants. *U. Bergthorsson, K. Adams, B. Thomason, J. Palmer ... Horizontal gene transfer from flowering plants to Gnetum. *H. Won, S. Renner ...
Inter-domain Horizontal Gene Transfer of Nickel-binding Superoxide Dismutase. bioRxiv , 426412. ... Inter-domain Horizontal Gene Transfer of Nickel-binding Superoxide Dismutase Citation:. Sutherland, K. M., Ward, L., Colombero ... C. R., & Johnston, D. T. (2021). Inter-domain Horizontal Gene Transfer of Nickel-binding Superoxide Dismutase. bioRxiv , 426412 ...
Horizontal Gene Transfer. Key Microorganisms. What kind of microbes do we typically find in this environment? Or associated ... This cell-cell attachment is based on plasmid-encoded and is subject to conjugal gene transfer. Dissemination of these plasmids ... This cell-cell attachment is based on plasmid-encoded and is subject to conjugal gene transfer. Dissemination of these plasmids ... This cell-cell attachment is based on plasmid-encoded and is subject to conjugal gene transfer. Dissemination of these plasmids ...
Horizontal Gene Transfer. Academic Press. p. 405. ISBN 978-0126801262. .. *^ a b c d e f g h i j k l m Timmis, Jeremy N.; ... horizontal gene transfer can occur again, and the cell can try again to have successful transfer of genes to the nucleus.[31] ... Ford Doolittle proposed a gene transfer ratchet mechanism to explain the unidirectional transfer of genes from the organelle ... Discusses theories on how mitochondria and chloroplast genes are transferred into the nucleus, and also what steps a gene needs ...
Author adminCategories Phylogenetic AnalysisTags Gene, Horizontal, MaxTiC, Phylogeny, Ranking Node, Transfer Leave a Reply ... MaxTiC - Ranking Nodes in a Phylogeny using inferred Horizontal Gene Transfers. MaxTiC. :: DESCRIPTION ... MaxTiC: Fast ranking of a phylogenetic tree by Maximum Time Consistency with lateral gene transfers ... Previous Previous post: ecceTERA 1.2.4 - Gene Tree Species Tree Reconciliation. Next Next post: AGapEs - Gap filling based on ...
To the Editor: Previous studies have suggested that protozoa may promote horizontal gene transfer among bacterial species (1,2 ... Oguri S, Matsuo J, Hayashi Y, Nakamura S, Hanawa T, Fukumoto T, Ciliates promote the transfer of the gene encoding the extended ... Because antibiotic resistance may be mediated by horizontal gene transfer, it is necessary to understand whether protozoa, ... even though ciliates promote the transfer of PMQR genes, they did not induce increased expression of these genes. Moreover, no ...
Horizontal Gene Transfer Experiments. Horizontal gene transfer of loci of heat resistance was assessed in plate matings as ... We also examined whether the LHRs would be amenable to horizontal gene transfer. Focusing on C604-10 and E. coli raw milk ... We next sought to determine whether the LHRs of FAM21805 and C604-10 were amenable to horizontal gene transfer. We tagged LHR1 ... Rossi, F., Rizzotti, L., Felis, G. E., and Torriani, S. (2014). Horizontal gene transfer among microorganisms in food: current ...
... and this loss and re-gain process influences the gene flow towards other lineages whenever it leads to serotype changes. ... A study of how the complex interaction between capsules and mobile genetic elements shapes gene flow in populations of ... Horizontal gene transfer Is the Subject Area "Horizontal gene transfer" applicable to this article? Yes. No. ...
Direct visualization of horizontal gene transfer. Babic A, Lindner AB, Vulic M, Stewart EJ, Radman M. Babic A, et al. Among ... Polymorphism of genes encoding SOS polymerases in natural populations of Escherichia coli. Bjedov I, Lecointre G, Tenaillon O, ...
Horizontal transfer of the nitrogen fixation gene cluster in the cyanobacterium Microcoleus chthonoplastes journal, September ... suggesting horizontal gene transfer into many clades. HgcA from marine metagenomes often formed distinct subtrees from those ... Nitrogenase Gene Amplicons from Global Marine Surface Waters Are Dominated by Genes of Non-Cyanobacteria journal, April 2011 * ... Evaluation of the Ion Torrent Personal Genome Machine for Gene-Targeted Studies Using Amplicons of the Nitrogenase Gene nifH ...
  • Antibiotic resistance genes in wastewater - studies on factors critical for assessing the risks. (
  • Antibiotic resistance genes (ARGs) can be present in both pathogens and harmless environmental bacteria. (
  • Pathogens can persist on hospital surfaces and plumbing for months to years, acquire new antibiotic resistance genes by horizontal gene transfer, and initiate outbreaks of hospital-associated infections by spreading to patients via healthcare worker s and visitors. (
  • Advancements in next-generation sequencing of bacterial genomes and metagenomes have expanded our ability to (1) identify species and track distinct strains, (2) comprehensively profile antibiotic resistance genes, and (3) resolve the mobile elements that facilit ate intra- and intercellular gene transfer. (
  • TetA (81.81%), tetB (72.72%), dfrA1 (63.63%), aac(3)-IV (63.63%), sul1 (63.63%) and aadA1 (45.45%) were the most commonly detected antibiotic resistance genes. (
  • A. baumannii strains with similar genetic cluster (ERIC-Type) had the same prevalence of antibiotic resistance, antibiotic resistance genes and virulence factors. (
  • to the ability to construct and shelter in biofilms, in individuals around the world without substantial risk and acquisition of antibiotic resistance genes ( 2 , 3 ). (
  • Muller and his colleagues scanned the genomes of 149 eukaryotes, and found acdS-like genes in 65 of them - 61 in fungi and 4 in parasitic microorganisms called oomycetes, including Phytophthora infestans, the microbe responsible for the Irish potato famine. (
  • More generally, we suggest that the expanding database of closely related eukaryotic genomes and the application of novel analytic methods will further underline the significant impact of foreign gene acquisition across the tree of life. (
  • A substantial amount of genetic information is inserted into or deleted from such genomes through the process of horizontal transfer. (
  • This seems to be a crude analogue of social learning, in which one species can learn the good tricks already discovered by another … the apparent ubiquity of horizontal gene transfer implies that microorganisms have an impressive capacity to actively alter their genomes in response to environmental stresses or opportunities. (
  • With the recent publication of several parasitic plant nuclear genomes, there has been considerable focus on such non-sexual exchange of genes. (
  • It sounds like the purest science fiction, but there it is in the above report: the engineered genomes are unstable, andas such will seek a more stable "home" and hencewill horizontally transfer yet again to other species. (
  • This work assembled the complete mt genomes from 12 mosses spanning the moss tree of life to assess the phylogenetic depth of the conserved mt gene content and order and the correlation between scattered sequence repeats and gene order lability in land plants. (
  • But the Human Genome Project led to faster, cheaper ways to sequence genes at scale, and a group of researchers including Alm and visiting professor Martin Polz began using those techniques to decode the genomes of environmental bacteria around 2008. (
  • New research reveals that hundreds of genes from bacteria, fungi and viruses have been integrated into plant genomes. (
  • Ecological epigenetics face a lot of challenges because the genomes of wild animals and plants have not been sequenced, meaning that scientists can't pinpoint which genes have been modified. (
  • Many years before any evidence for horizontal transfer of genes and genomes entered the mainstream of biological thought, Kozo-Polyansky suggested that cells are in fact not just elementary units of life but cooperative systems (he in fact used the word "system").The original Russian book was published in 1924, and its little-known author died in 1957. (
  • The most well-known and dramatic form of HGT represents intracellular gene transfer from endosymbionts to the host nuclear genome. (
  • These gene transfers are often physically linked in the genome and show more than two-fold functional enrichment in carbohydrate activating enzymes associated with plant cell wall degradation. (
  • The TWiM team marvels over the finding of a completely nitrifying Nitrospira, and horizontal gene transfer from Wolbachia into an animal genome. (
  • In this study, the genome of this strain was sequenced and analyzed with a focus on gene transfer from phylogenetically distant organisms. (
  • As mobile genetic elements transferred from phylogenetically distant organisms, putative inteins were identified in the GyrB and DnaE proteins encoded in the genome of strain Tokyo 01 T . Genes involved in DNA recombination and repair were enriched in comparison to the closest relatives in the same family. (
  • Using genome analysis to compare the complete genome sequences of different species, they looked for genes in plants which had originated from bacteria, viruses, fungi or animals, and found a total of 593 gene families. (
  • And some ecologists are beginning to think that epigenetic factors might be modifying genes while leaving the genome intact. (
  • Accumulations of TEs (TE islands) comprising 7.18% of the genome evolve faster than other regions with regard to single-nucleotide variants, gene/exon duplications and deletions and gene homology. (
  • The distinct organization of TE islands, their gene composition and their regulation by the genome adds compelling evidence for the role of TEs as players in differentiation, adaptation and speciation. (
  • In participating UK research institutions, investigators can publish open access in Genome Research, Genes & Development, RNA, and Learning & Memory without article publication charges and all staff can read the entire renowned Cold Spring Harbor journal collection. (
  • This thesis builds on that project, by improving our ability to identify gene families --- groups of genes in different strains that are related. (
  • Here, we show that these swarm antagonisms promote transformation-mediated horizontal gene transfer between strains of low relatedness. (
  • Gene transfer between interacting non-kin strains is largely unidirectional, from killed cells of the donor strain to surviving cells of the recipient strain. (
  • We hypothesize that KD-mediated competence in response to the encounter of distinct neighbouring strains could maximize the probability of efficient incorporation of novel alleles and genes that have proved to function in a genomically and ecologically similar context. (
  • The actual origins of acquired resistance genes are unknown, but environmental microbes, including the strains producing antimicrobial agents, are believed to be important sources (4,5). (
  • We will be able to systematically classify genes as resistant or permissive to transfer, examine the effect of the function and position in metabolic and regulatory networks on resistance to transfer, as well as identify any genes with substantial intrinsic benefits. (
  • Sometimes the resistance was rapid and so indicated a transfer of resistance between bacteria rather than independent adaptations. (
  • Watch this 10-minute video on MRSA to learn about how resistance genes can be transferred between bacteria. (
  • Briefly explain how horizontal gene transfer could lead to antibiotic resistance spreading from commensal bacteria to pathogenic, disease-causing bacteria. (
  • Horizontal gene transfer describes the movement of genetic material between organisms of different species - events which are common in bacteria and are responsible for the rapid spread of antibiotic resistance, for instance. (
  • A cluster and humans coming into contact with the animals (farm that includes three genes, vanH , vanA , and vanX , is required for high-level resistance to glycopeptides. (
  • Furthermore, nucleotide sequences related to the cluster vanHAX are present in this DNA, suggesting that the prolonged use of avoparcin in agriculture led to the uptake of glycopeptide resistance genes by animal commensal bacteria, which were subsequently transferred to humans. (
  • Resistance arises by mutation (influencing the target or efflux of the antimicrobial agent) or by the acquisition of resistance genes (encoding antimicrobial or target alter- ation, or alternate pathways) (2,3). (
  • Antimicrobial resistance occurs through different mechanisms, which include spontaneous (natural) genetic mutations and horizontal transfer of resistant genes through deoxyribonucleic acid (DNA). (
  • This report presents the status of AMR in Africa by analysing the main types of resistance and the underlying genes where possible. (
  • This briefing note is limited to consideration of antibacterial agents, antibacterial resistance and antibacterial resistance genes. (
  • Natural Horizontal Gene Transfer of Antimicrobial Resistance Genes in Campylobacter spp. (
  • [ 8 ] Using a previously described method for detection of macrolide resistance in Mycobacteroides abscessus , [ 9 ] we did not detect a functional erm gene. (
  • After analysing the organisms' genetic family trees, the researchers determined that the most likely explanation was that three different kinds of bacterium had donated the gene to the fungi and oomycetes in a total of 15 different horizontal-gene-transfer events. (
  • Through the introduction of novel physiological traits from distantly related organisms, horizontal gene transfer often causes drastic changes in the ecological and pathogenic character of bacterial species and thereby promotes microbial diversification and speciation. (
  • We now understand that bacteria, as well as higher organisms, can trade genetic material via several different mechanisms collectively referred to as horizontal gene transfer. (
  • Organisms intelligently adapt to environmental challenges and genes show up in the wrong place. (
  • While the concept is sometimes extended to include transfers between cellular compartments (e.g. chloroplast to mitochondrion), we here refer to HGT as exchange of genetic material between organisms and consider it distinct from intracellular transfers. (
  • Once GMOs are unleashed in the environment, there is absolutely nothing to stop the natural occurrence of horizontal gene transfer to non-GMO organisms, especially considering GMOs' increased tendency to do so. (
  • This work presents multiple lines of evidence documenting horizontal gene transfer (HGT) between the mitogenomes of fungi and the ancestors of the orchids, and demonstrates that the length intergenic spacer regions of angiosperm mitogenome can effectively fossilize the genomic remains of ancient, non-plant organisms. (
  • Selection for and acquisition of this "survival" plasmid by pathogenic organisms, e.g., in food production environments, may pose great concern and emphasizes the need to screen for the presence of LHR genes in isolates. (
  • Some of these genes were also related to those of organisms outside of the class Deltaproteobacteria, suggesting that they were acquired by horizontal gene transfer from diverse bacteria. (
  • The ability to pick up used genes and spare parts from other organisms' DNA junkyards may allow tardigrades to survive extreme stress , such as desiccation, radiation and even a trip to space and back, researchers report online November 23 in the Proceedings of the National Academy of Sciences . (
  • GENE INVASION Tardigrades get 17.5 percent of their genes from other organisms, the most of any animal. (
  • Genetics is the study of genes , heredity , and the variation of organisms , as well as the medical practice of diagnosing, treating, and counseling patients with genetic disorders . (
  • In pathogenic microorganisms, particularly when rates of horizontal gene transfer are high due to processes such as DNA transformation that occurs with some organisms inhabiting the upper respiratory tract of humans, evolutionary lineages can still be analysed by considering DNA sequence change that occurs in several genes. (
  • In addition to the specific set of gene functions overexpressed in early and mature oral biofilms, as detected through the short-reads dataset, the long-reads approach detected specific changes when comparing the metatranscriptome of the same individual before and after a meal, which can narrow down the list of organisms responsible for acid production and therefore potentially involved in dental caries. (
  • The mitogenomes are 265,696 and 275,898 bp in length and contain a typical set of mitochondrial genes, with 10 missing or pseudogenized genes often lost from angiosperm mitogenomes. (
  • Based on phylogenetic analysis of mitochondrial genes from across angiosperms and similarity-based searches, there is little to no indication of HGT into the Cuscuta mitogenomes. (
  • Unparalleled replacement of native mitochondrial genes by foreign homologs in a holoparasitic plant. (
  • The sequencing of the complete mtDNA of L. mirabile revealed the unprecedented acquisition of host-derived mitochondrial genes, representing 80% of the protein-coding gene content, and represents a stunning example of the potential effect of rampant HGT on plant mitochondria. (
  • The predominant method of molecular subtyping of B. pseudomallei is multilocus sequence typing (MLST), which is based on a comparison of the alleles of 7 housekeeping genes to generate a sequence type (ST) ( 2 ). (
  • Gene flow (also known as gene migration ) is the transfer of alleles of genes from one population to another. (
  • The TWiM crew ponders the question of how a bacterium finds its middle when dividing, then divulge the transfer of interbacterial antagonism genes to eukaryotes, where they may function in innate defense. (
  • Horizontal Gene Transfer in Eukaryotes: Not if, but How Much? (
  • Such episodes of transfer typically involve hundreds of genes and are thought to be possible only in the case of endosymbiosis. (
  • This proposal will outline a systematic experimental approach to elucidate factors that select for or against horizontally transferred genes, by pursuing three objectives. (
  • Risk scenarios where novel plant transgenes transfer horizontally into bacteria have been addressed in numerical theoretical assessments and experimental studies. (
  • Here we present a stochastic model to better understand the initial establishment and population dynamics of rare bacterial transformants carrying horizontally acquired (trans)genes. (
  • Here, we used Illumina MiSeq to sequence amplicons generated from the V4 region of the 16S rRNA gene to investigate the gut microbiome of two free-ranging sympatric Namibian carnivore species, the cheetah (Acinonyx jubatus) and the black-backed jackal (Canis mesomelas). (
  • The use of importance of different sources of human infection has hin- nucleotide sequence data directly accesses the variation in the dered the development of effective disease-control measures targeted gene, and the technology employed is readily dissem- and is a major challenge in preventing human disease. (
  • Using DNA extracted from bacteria in the dental plaque of mother/child pairs, a sequence of the S. mutans spaP gene was amplified using PCR. (
  • The studies in Salmonella are focused in the regulation of the pathogenicity island 1 genes, which are involved in the invasion of epithelial cells. (
  • Virulence genes identification and characterization revealed the presence of the Yersinia High Pathogenicity Island (HPI) in Salmonella from Brazil. (
  • Huang J, Mullapudi N, Lancto CA, Scott M, Abrahamsen MS, Kissinger JC: Phylogenomic evidence supports past endosymbiosis , intracellular and horizontal gene transfer in Cryptosporidium parvum. (
  • So when biologist Thomas Boothby of the University of North Carolina at Chapel Hill and colleagues discovered bacterial genes mixed in to the DNA of Hypsibius dujardini tardigrades, "our initial thought was, 'this is actually a mistake. (
  • Previously, similarity was measured only by comparing two genes' DNA sequences, ignoring their positions on the organism's DNA. (
  • Various studies have found that bacterial sequences often do not form the predicted evolutionary tree, and in such cases horizontal gene transfer is the typical explanation. (
  • Bioinformatic analysis of marker gene sequences also requires considerable expertise. (
  • Using a conservative phylogenomic approach, we analyzed genomic data from the fungal pathogen Magnaporthiopsis incrustans in the order Magnaporthales and identified two instances of exclusive sharing of HGT-derived gene markers between Magnaporthales and another lineage of plant-pathogenic fungi in the genus Colletotrichum. (
  • In the case of pathogenic bacteria, the modulation of gene expression is crucial, since during the infectious process they need to encounter different many different niches of the host. (
  • Ancient mitochondrial gene transfer between fungi and the orchids. (
  • This number is far greater than previously thought, and were transferred especially from microbes, such as bacteria and fungi. (
  • The ammonium transporter gene, acquired from fungi, helps plants absorb nitrogen from soil for growth. (
  • Around 500 million years ago, aquatic plants migrated from water to land, and they may have been able to do it with genes adopted from bacteria, fungi and viruses. (
  • Thus determining the phylogenetic history of a species can not be done conclusively by determining evolutionary trees for single genes. (
  • Phylogenetic conflicts observed in animal and plant systems have often been explained by hybridization, incomplete lineage sorting (ILS), or horizontal gene transfer. (
  • Horizontal gene transfer (HGT) is an important mechanism by which bacteria recombine and acquire novel genes and functions. (
  • They both have been explained by horizontal gene transfer, a mechanism that evolutionists are increasingly using to explain the origin of the species. (
  • Conjugation may be another mechanism that bacteria develop to transfer plasmid to the adjacent cells. (
  • The observation of fecal excretion of radioactive strontium weeks to decades after an oral exposure or over shorter time periods after an intravenous exposure suggests the existence of a mechanism for transfer of absorbed strontium into gastrointestinal tract, either from the bile or directly from the plasma (ATSDR 2001e). (
  • In our research group, we are studying different mechanisms of gene expression regulation in Salmonella enterica and Escherichia coli. (
  • PCR Primer Design for 16S rRNAs for Experimental Horizontal Gene Transfer Test in Escherichia coli. (
  • In the vancomycin producer Amycolatopsis orientalis C329.2, homologs of these genes are present, suggesting an origin for the cluster. (
  • We have described a regulatory circuit, composed of three proteins, that controls the expression of genes involved in the conjugation of IncHI1 plasmids in response to changes in the environmental conditions. (
  • Traditionally, scientists thought that genes in plants and animals have only moved via vertical gene transfer, where genes are passed down from parents to offspring, and new genes and traits are achieved through mutations occurring. (
  • Compared with mutations from vertical gene transfer, HGT enables plants to gain new traits rapidly, and some of these new traits could help plants adapt to a drastically different environment, like when they moved from water to land. (
  • Profiles of mutations in hepatitis B virus surface and polymerase genes isolated from treatment-naïve Nigerians infected with genotype E. (
  • Future research with a translational approach will help dental esthetics, identify new mutations or genes, contributing to the evolution in the way of classifying, diagnosing and genes. (
  • These imprudent uses and abuses of antibiotics and other antimicrobial agents contribute to the extensive presence of their residues, their metabolites, multiple antimicrobial-resistant bacteria and their functional genes in human and animal wastes, in landfil s and their leachates, in water, soil and sediments and in water-dependent food crops, such as seafood and produce. (
  • Pili are filamentous surface extensions that play roles in bacterial and archaeal cellular processes such as adhesion, biofilm formation, motility, cell-cell communication, DNA uptake and horizontal gene transfer. (
  • The nifH gene, which codes for the iron protein of the nitrogenase enzyme, is the most widely established molecular marker for the study of nitrogen-fixing microorganisms (diazotrophs) in nature. (
  • In this study, 16S rRNA gene amplicon pyrosequencing was applied in order to explore the structure of the bacterial community inhabiting the camel rumen. (
  • In this study, we determined the bacterial diversity profile of the Mexico City metro by massive sequencing of the 16S rRNA gene. (
  • The genes of microbes made the jump into green algae and plants hundreds of millions of years ago, suggesting the evolution of plants from water to land might have been driven by these events, according to a new study . (
  • They also identified two major HGT events - during the early evolution of charophytes and the origin of land plants - when over a hundred gene families hopped over from microbes into plants. (
  • A phylogenomic perspective on gene tree conflict and character evolution in Caprifoliaceae using target enrichment data, with Zabelioideae recognized as a new subfamily[J]. J Syst Evol, 2021, 59(5): 897-914. (
  • Phylotranscriptomics reveals extensive gene duplication in the subtribe Gentianinae (Gentianaceae) [J]. J Syst Evol, 2021, 59(6): 1198-1208. (
  • Differential distribution of the wlan and cgtB genes, associated with Guillain-Barré syndrome, in Campylobacter jejuni isolates from humans, broiler chickens, and wild birds. (
  • We now understand that epigenetic and horizontal gene transfer mechanisms, respectively, often account for such phenomena. (
  • Because biofilms bring cells together in close physical proximity, the process of biofilm formation is coupled with additional social systems and mechanisms fundamental to microbiology, including quorum sensing (and other forms of cell-to-cell communication), horizontal gene transfer (HGT) and the secretion of enzymes that degrade complex material, causing the ECM to act like a kind of shared external digestive system [ 3 ],[ 5 ]. (
  • This result indicates that social interactions can override mechanistic barriers to horizontal gene transfer. (
  • Physical barriers to gene flow are usually, but not always, natural. (
  • orthogonal exPeriMental changes and pathways induced by EGE investigated the impact of aSSeSSMent of ePigenetic environmental factors in cancer causation, both current H. pylori infection and driver geneS and their link to underpinning studies of etiology e , pigenetic memory of past (eradicated) environMental carcinogenS carcinogen evaluation, and prevention. (
  • The second objective is to examine the effect of evolutionary divergence on HGT, by determining whether genes from closely related species are more permissive to transfer than those from more divergent species. (
  • For in order for the evolutionary story to make sense, we must believe that evolution created horizontal gene transfer. (
  • Now, to account for the codes "universality and optimality," recent evolutionary speculation calls for a massive level of horizontal gene transfer which was "likely to be present in early communal life" and led to "innovation-sharing protocols. (
  • Furthermore, a number of unique characteristics of microbial species, such as horizontal gene transfer, the production of public goods, toxin and antibiotic production, rapid evolution, and feedbacks between the microbiome and its host, are not easily accommodated by current ecological and evolutionary theory. (
  • DNA alone was considered right in evolutionary changes and genetics had grown enormously in decoding the gene sequencing of humans and other species as well. (
  • Stephen J. Gould wrote: "Few evolutionary biologists recognize this curious terminological odyssey making Darwin himself the ultimate, if indirect, source of our modern term 'gene' " ( The Structure of Evolutionary Theory ). (
  • A non-random distribution of gene families, larvae/adult specific gene expression and signs of differential methylation in TE islands indicate intragenomic differences in regulation, evolutionary rates and coalescent effective population size. (
  • Conjugative plasmids are vehicles for horizontal gene transfer. (
  • Horizontal gene transfer happens more often in bdelloid rotifers that undergo desiccation than in those that live in aquatic environments and can't stand to be dried out, the researchers report online November 4 in BMC Biology . (
  • But further testing showed that the tardigrades had incorporated into their own DNA genes from more than 1,300 bacterial species, 40 archaea, 91 species of fungus, 45 plant species and six viruses. (
  • The few known examples from prokaryotes and viruses may be the result of horizontal gene transfers. (
  • Viruses can transfer genes between species. (
  • A large-scale phylogeny-based prokaryotic HGT detection procedure across nine sequenced diatoms showed that 3-5% of their proteome has a horizontal origin and a large influx occurred at the ancestor of diatoms. (
  • Consider: these foods are the product of genetic engineering, of what scientists call "horizontal gene transfer" from one species to another, without any reproduction. (
  • This final step was explained further when Tian Xu and a team of scientists at Yale Medical Center in 2010 showed that stress (emotional, work-related and other forms) causes cellular inflammation, which in turn stimulated two cancer causing genes inside the cell. (
  • These bacteria may be acquired through both vertical and horizontal transmission, the mothers being the main source of infection through S. mutans in their children 3 . (
  • Recombination occurring between genes from different species. (
  • The loosening of terminal adhesives of epigenic proteins can do a lot of transformation in mutation of genes in evolution. (
  • According to the researchers, these acquired genes may influence plant physiology and development, ultimately leading to better adaptation of plants to their environments and allowing them to live on land. (
  • Vancaester E, Depuydt T, Osuna C, Vandepoele K. Comprehensive and functional analysis of horizontal gene transfer events in diatoms. (
  • The intimate association between parasitic plants and their hosts favours the exchange of genetic material, potentially leading to horizontal gene transfer (HGT) between plants. (
  • The altered need for photosynthetic capacity has impacted the size and gene content of plastomes of many parasitic plants [ 16 , 17 ]. (
  • I have suspected that horizontal gene transfer helped plants to move from water to land, but we didn't know how big a role it played until now. (
  • This research indicates that HGT is active in charophytes and all major groups of land plants, although interestingly more recently acquired genes are much less prevalent in seed plants. (
  • Many of these genes are known to perform important biological functions in plants. (
  • For example, the late embryogenesis abundant (LEA) genes, which come from bacteria, help plants adapt to a drier environment. (
  • Many foreign genes in these plants have unknown functions, and future research might help identify useful genes that can one day be transferred into crops to help augment them. (
  • IMSEAR at SEARO: Horizontal gene transfer and bacterial diversity. (
  • Dutta C, Pan A. Horizontal gene transfer and bacterial diversity. (
  • In common with multilocus enzyme organism's wide distribution, high levels of genetic and anti- electrophoresis, MLST indexes variation in housekeeping genic diversity, and a lack of representative population sam- genes, which evolve slowly as they are under stabilizing selec- ples (9). (
  • 2012). Therein, we used the widespread common primers Bac8f and UN1541r to acquire a virtually full-length gene. (
  • Extensive horizontal gene transfer in ureaplasmas from humans questions the utility of serotyping for diagnostic purposes. (
  • There are a number of factors that affect the rate of gene flow between different populations. (
  • Behavioral differences in geographically isolated populations can prevent gene flow and lead to speciation . (
  • By measuring the frequencies, the rate of gene flow between the two populations can be measured, showing that gene flow is greater in the Northern U.S. than in the South. (
  • The transcriptomic profile of several adhesion genes was confirmed through qPCR by measuring expression of fimbriae-associated genes. (
  • The genomic data suggested significant genetic transfer among filamentous gliding bacteria in phylogenetically dispersed lineages including filamentous sulfate reducers. (
  • This cell-cell attachment is based on plasmid-encoded and is subject to conjugal gene transfer. (
  • Horizontal gene transfer (HGT) may be broadly defined as the movement of genetic material between species by a means other than normal reproduction (e.g. fusion of gametes). (
  • Horizontal gene transfer (HGT), the movement of genetic material across branches of the tree of life, is well established in prokaryotes and uncontroversial. (
  • Immigration may result in the addition of new genetic material to the established gene pool of a particular species or population, and conversely emigration may result in the removal of genetic material. (
  • The survival of bacteria to adverse conditions depends on its ability to modulate gene expression, to provide the appropriate gene products for the adaptation to the new environmental conditions. (
  • Although the composition of oral biofilms is well established, the active portion of the bacterial community and the patterns of gene expression in vivo have not been studied. (
  • We could identify some gene expression patterns characteristic for early and mature oral biofilms. (
  • Among the signaling pathways regulated by GSK3s, the Wnt canonical pathway is the most well described, with GSK3β inhibition triggering an increase in β -catenin protein levels and its nuclear translocation to activate target gene expression ( Doble and Woodgett, 2003 ). (
  • Further experiments demonstrated that resveratrol had little effect on VACV early gene expression, while it suppressed VACV DNA synthesis, and subsequently post-replicative gene expression. (
  • When National Geographic caught up with the author at his home in Montana, he explained how the discovery of a new "third kingdom" of life changed our understanding of evolution, how so-called kissing bugs can move DNA from one species to another, and why the gene-editing tool CRISPR presents exciting new possibilities, as well as ethical challenges. (