Genome: The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.Genome, Bacterial: The genetic complement of a BACTERIA as represented in its DNA.Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.Genome, Human: The complete genetic complement contained in the DNA of a set of CHROMOSOMES in a HUMAN. The length of the human genome is about 3 billion base pairs.Genome, Mitochondrial: The genetic complement of MITOCHONDRIA as represented in their DNA.Genome, Fungal: The complete gene complement contained in a set of chromosomes in a fungus.Genome Size: The amount of DNA (or RNA) in one copy of a genome.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Genome, Archaeal: The genetic complement of an archaeal organism (ARCHAEA) as represented in its DNA.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Genome, Insect: The genetic complement of an insect (INSECTS) as represented in its DNA.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Genome, Protozoan: The complete genetic complement contained in a set of CHROMOSOMES in a protozoan.Genomics: The systematic study of the complete DNA sequences (GENOME) of organisms.Genome, Chloroplast: The genetic complement of CHLOROPLASTS as represented in their DNA.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Genome, Helminth: The genetic complement of a helminth (HELMINTHS) as represented in its DNA.Open Reading Frames: 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).Genome, Plastid: The genetic complement of PLASTIDS as represented in their DNA.Sequence Alignment: 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.Synteny: The presence of two or more genetic loci on the same chromosome. Extensions of this original definition refer to the similarity in content and organization between chromosomes, of different species for example.Human Genome Project: A coordinated effort of researchers to map (CHROMOSOME MAPPING) and sequence (SEQUENCE ANALYSIS, DNA) the human GENOME.DNA, Viral: Deoxyribonucleic acid that makes up the genetic material of viruses.Molecular Sequence Data: 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.Gene Order: The sequential location of genes on a chromosome.Computational Biology: 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.Genetic Variation: Genotypic differences observed among individuals in a population.Models, Genetic: 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.Amino Acid Sequence: 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.Databases, Genetic: Databases devoted to knowledge about specific genes and gene products.Recombination, Genetic: 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.Species Specificity: 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.Multigene Family: 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)Chromosomes, Artificial, Bacterial: DNA constructs that are composed of, at least, a REPLICATION ORIGIN, for successful replication, propagation to and maintenance as an extra chromosome in bacteria. In addition, they can carry large amounts (about 200 kilobases) of other sequence for a variety of bioengineering purposes.Gene Duplication: Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.Repetitive Sequences, Nucleic Acid: Sequences of DNA or RNA that occur in multiple copies. There are several types: INTERSPERSED REPETITIVE SEQUENCES are copies of transposable elements (DNA TRANSPOSABLE ELEMENTS or RETROELEMENTS) dispersed throughout the genome. TERMINAL REPEAT SEQUENCES flank both ends of another sequence, for example, the long terminal repeats (LTRs) on RETROVIRUSES. Variations may be direct repeats, those occurring in the same direction, or inverted repeats, those opposite to each other in direction. TANDEM REPEAT SEQUENCES are copies which lie adjacent to each other, direct or inverted (INVERTED REPEAT SEQUENCES).RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Genes, Viral: The functional hereditary units of VIRUSES.Software: Sequential operating programs and data which instruct the functioning of a digital computer.Molecular Sequence Annotation: The addition of descriptive information about the function or structure of a molecular sequence to its MOLECULAR SEQUENCE DATA record.DNA Transposable Elements: 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.Base Composition: The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.DNA, Mitochondrial: Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.Sequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Mutation: 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.Cloning, Molecular: 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.Contig Mapping: Overlapping of cloned or sequenced DNA to construct a continuous region of a gene, chromosome or genome.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Conserved Sequence: A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.Viral Proteins: Proteins found in any species of virus.Gene Transfer, Horizontal: 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).Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Retroelements: Elements that are transcribed into RNA, reverse-transcribed into DNA and then inserted into a new site in the genome. Long terminal repeats (LTRs) similar to those from retroviruses are contained in retrotransposons and retrovirus-like elements. Retroposons, such as LONG INTERSPERSED NUCLEOTIDE ELEMENTS and SHORT INTERSPERSED NUCLEOTIDE ELEMENTS do not contain LTRs.Nucleic Acid Hybridization: Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)Databases, Nucleic Acid: Databases containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS; NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.Chromosomes, Plant: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.Expressed Sequence Tags: Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.High-Throughput Nucleotide Sequencing: Techniques of nucleotide sequence analysis that increase the range, complexity, sensitivity, and accuracy of results by greatly increasing the scale of operations and thus the number of nucleotides, and the number of copies of each nucleotide sequenced. The sequencing may be done by analysis of the synthesis or ligation products, hybridization to preexisting sequences, etc.Pseudogenes: Genes bearing close resemblance to known genes at different loci, but rendered non-functional by additions or deletions in structure that prevent normal transcription or translation. When lacking introns and containing a poly-A segment near the downstream end (as a result of reverse copying from processed nuclear RNA into double-stranded DNA), they are called processed genes.Physical Chromosome Mapping: Mapping of the linear order of genes on a chromosome with units indicating their distances by using methods other than genetic recombination. These methods include nucleotide sequencing, overlapping deletions in polytene chromosomes, and electron micrography of heteroduplex DNA. (From King & Stansfield, A Dictionary of Genetics, 5th ed)Polymerase Chain Reaction: 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.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Genomic Instability: An increased tendency of the GENOME to acquire MUTATIONS when various processes involved in maintaining and replicating the genome are dysfunctional.Genes, Bacterial: The functional hereditary units of BACTERIA.Polyploidy: The chromosomal constitution of a cell containing multiples of the normal number of CHROMOSOMES; includes triploidy (symbol: 3N), tetraploidy (symbol: 4N), etc.Genetic Markers: A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.DNA: 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).Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Genes, Plant: The functional hereditary units of PLANTS.Genome, Microbial: The genetic complement of a microorganism as represented in its DNA or in some microorganisms its RNA.Plasmids: 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.Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Genome Components: The parts of a GENOME sequence that are involved with the different functions or properties of genomes as a whole as opposed to those of individual GENES.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Sequence Homology: The degree of similarity between sequences. Studies of AMINO ACID SEQUENCE HOMOLOGY and NUCLEIC ACID SEQUENCE HOMOLOGY provide useful information about the genetic relatedness of genes, gene products, and species.Oryza sativa: Annual cereal grass of the family POACEAE and its edible starchy grain, rice, which is the staple food of roughly one-half of the world's population.Chromosomes: In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Bacterial Proteins: Proteins found in any species of bacterium.DNA, Intergenic: Any of the DNA in between gene-coding DNA, including untranslated regions, 5' and 3' flanking regions, INTRONS, non-functional pseudogenes, and non-functional repetitive sequences. This DNA may or may not encode regulatory functions.Gene Rearrangement: The ordered rearrangement of gene regions by DNA recombination such as that which occurs normally during development.Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Polymorphism, Single Nucleotide: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.Chromosomes, Bacterial: Structures within the nucleus of bacterial cells consisting of or containing DNA, which carry genetic information essential to the cell.Oligonucleotide Array Sequence Analysis: Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.DNA Replication: The process by which a DNA molecule is duplicated.Mutagenesis, Insertional: Mutagenesis where the mutation is caused by the introduction of foreign DNA sequences into a gene or extragenic sequence. This may occur spontaneously in vivo or be experimentally induced in vivo or in vitro. Proviral DNA insertions into or adjacent to a cellular proto-oncogene can interrupt GENETIC TRANSLATION of the coding sequences or interfere with recognition of regulatory elements and cause unregulated expression of the proto-oncogene resulting in tumor formation.DNA Restriction Enzymes: Enzymes that are part of the restriction-modification systems. They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA. Cleavage yields random or specific double-stranded fragments with terminal 5'-phosphates. The function of restriction enzymes is to destroy any foreign DNA that invades the host cell. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms. They are also used as tools for the systematic dissection and mapping of chromosomes, in the determination of base sequences of DNAs, and have made it possible to splice and recombine genes from one organism into the genome of another. EC 3.21.1.Cluster Analysis: 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.Genetic Linkage: The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.Gene Library: A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.Gene Dosage: The number of copies of a given gene present in the cell of an organism. An increase in gene dosage (by GENE DUPLICATION for example) can result in higher levels of gene product formation. GENE DOSAGE COMPENSATION mechanisms result in adjustments to the level GENE EXPRESSION when there are changes or differences in gene dosage.Codon: A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).DNA Primers: 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.Bacteriophages: Viruses whose hosts are bacterial cells.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Selection, Genetic: Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Introns: Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.Terminal Repeat Sequences: Nucleotide sequences repeated on both the 5' and 3' ends of a sequence under consideration. For example, the hallmarks of a transposon are that it is flanked by inverted repeats on each end and the inverted repeats are flanked by direct repeats. The Delta element of Ty retrotransposons and LTRs (long terminal repeats) are examples of this concept.User-Computer Interface: The portion of an interactive computer program that issues messages to and receives commands from a user.Prophages: 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.Blotting, Southern: 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.INDEL Mutation: A mutation named with the blend of insertion and deletion. It refers to a length difference between two ALLELES where it is unknowable if the difference was originally caused by a SEQUENCE INSERTION or by a SEQUENCE DELETION. If the number of nucleotides in the insertion/deletion is not divisible by three, and it occurs in a protein coding region, it is also a FRAMESHIFT MUTATION.Microsatellite Repeats: A variety of simple repeat sequences that are distributed throughout the GENOME. They are characterized by a short repeat unit of 2-8 basepairs that is repeated up to 100 times. They are also known as short tandem repeats (STRs).Escherichia coli: 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.Genes, Mitochondrial: Genes that are located on the MITOCHONDRIAL DNA. Mitochondrial inheritance is often referred to as maternal inheritance but should be differentiated from maternal inheritance that is transmitted chromosomally.DNA, Chloroplast: Deoxyribonucleic acid that makes up the genetic material of CHLOROPLASTS.Gene Deletion: A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.Genomic Library: A form of GENE LIBRARY containing the complete DNA sequences present in the genome of a given organism. It contrasts with a cDNA library which contains only sequences utilized in protein coding (lacking introns).Comparative Genomic Hybridization: A method for comparing two sets of chromosomal DNA by analyzing differences in the copy number and location of specific sequences. It is used to look for large sequence changes such as deletions, duplications, amplifications, or translocations.Arabidopsis: A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.RNA, Transfer: 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.Vertebrates: Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.Prokaryotic Cells: Cells lacking a nuclear membrane so that the nuclear material is either scattered in the cytoplasm or collected in a nucleoid region.Symbiosis: 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.Sequence Analysis, RNA: A multistage process that includes cloning, physical mapping, subcloning, sequencing, and information analysis of an RNA SEQUENCE.Promoter Regions, Genetic: 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.Interspersed Repetitive Sequences: 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.RNA, Messenger: 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.Plants: 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.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Virulence: The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.Inverted Repeat Sequences: Copies of nucleic acid sequence that are arranged in opposing orientation. They may lie adjacent to each other (tandem) or be separated by some sequence that is not part of the repeat (hyphenated). They may be true palindromic repeats, i.e. read the same backwards as forward, or complementary which reads as the base complement in the opposite orientation. Complementary inverted repeats have the potential to form hairpin loop or stem-loop structures which results in cruciform structures (such as CRUCIFORM DNA) when the complementary inverted repeats occur in double stranded regions.RNA Viruses: Viruses whose genetic material is RNA.Plastids: 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.Virus Integration: Insertion of viral DNA into host-cell DNA. This includes integration of phage DNA into bacterial DNA; (LYSOGENY); to form a PROPHAGE or integration of retroviral DNA into cellular DNA to form a PROVIRUS.Bacteria: 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.Genes, Archaeal: The functional genetic units of ARCHAEA.Sorghum: A plant genus of the family POACEAE. The grain is used for FOOD and for ANIMAL FEED. This should not be confused with KAFFIR LIME or with KEFIR milk product.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Gene Expression Regulation, Viral: Any of the processes by which cytoplasmic factors influence the differential control of gene action in viruses.DNA, Circular: Any of the covalently closed DNA molecules found in bacteria, many viruses, mitochondria, plastids, and plasmids. Small, polydisperse circular DNA's have also been observed in a number of eukaryotic organisms and are suggested to have homology with chromosomal DNA and the capacity to be inserted into, and excised from, chromosomal DNA. It is a fragment of DNA formed by a process of looping out and deletion, containing a constant region of the mu heavy chain and the 3'-part of the mu switch region. Circular DNA is a normal product of rearrangement among gene segments encoding the variable regions of immunoglobulin light and heavy chains, as well as the T-cell receptor. (Riger et al., Glossary of Genetics, 5th ed & Segen, Dictionary of Modern Medicine, 1992)Genetic Loci: Specific regions that are mapped within a GENOME. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of CHROMOSOME 6. Many well known genetic loci are also known by common names that are associated with a genetic function or HEREDITARY DISEASE.Chromosomes, Human: Very long DNA molecules and associated proteins, HISTONES, and non-histone chromosomal proteins (CHROMOSOMAL PROTEINS, NON-HISTONE). Normally 46 chromosomes, including two sex chromosomes are found in the nucleus of human cells. They carry the hereditary information of the individual.Short Interspersed Nucleotide Elements: Highly repeated sequences, 100-300 bases long, which contain RNA polymerase III promoters. The primate Alu (ALU ELEMENTS) and the rodent B1 SINEs are derived from 7SL RNA, the RNA component of the signal recognition particle. Most other SINEs are derived from tRNAs including the MIRs (mammalian-wide interspersed repeats).Genetic Vectors: 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.Genetic Engineering: 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.Segmental Duplications, Genomic: Low-copy (2-50) repetitive DNA elements that are highly homologous and range in size from 1000 to 400,000 base pairs.DNA, Complementary: Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.Polymorphism, Genetic: The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.Drosophila melanogaster: A species of fruit fly much used in genetics because of the large size of its chromosomes.Eukaryotic Cells: Cells of the higher organisms, containing a true nucleus bounded by a nuclear membrane.Metabolic Networks and Pathways: Complex sets of enzymatic reactions connected to each other via their product and substrate metabolites.GC Rich Sequence: A nucleic acid sequence that contains an above average number of GUANINE and CYTOSINE bases.Mammals: Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Long Interspersed Nucleotide Elements: Highly repeated sequences, 6K-8K base pairs in length, which contain RNA polymerase II promoters. They also have an open reading frame that is related to the reverse transcriptase of retroviruses but they do not contain LTRs (long terminal repeats). Copies of the LINE 1 (L1) family form about 15% of the human genome. The jockey elements of Drosophila are LINEs.Transcriptome: The pattern of GENE EXPRESSION at the level of genetic transcription in a specific organism or under specific circumstances in specific cells.Hybridization, Genetic: The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Pan troglodytes: The common chimpanzee, a species of the genus Pan, family HOMINIDAE. It lives in Africa, primarily in the tropical rainforests. There are a number of recognized subspecies.Eukaryota: 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.Archaea: 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.Quantitative Trait Loci: Genetic loci associated with a QUANTITATIVE TRAIT.Genes, Duplicate: Two identical genes showing the same phenotypic action but localized in different regions of a chromosome or on different chromosomes. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Angiosperms: Members of the group of vascular plants which bear flowers. They are differentiated from GYMNOSPERMS by their production of seeds within a closed chamber (OVARY, PLANT). The Angiosperms division is composed of two classes, the monocotyledons (Liliopsida) and dicotyledons (Magnoliopsida). Angiosperms represent approximately 80% of all known living plants.Sequence Deletion: Deletion of sequences of nucleic acids from the genetic material of an individual.Capsid: The outer protein protective shell of a virus, which protects the viral nucleic acid.Tetraodontiformes: A small order of primarily marine fish containing 340 species. Most have a rotund or box-like shape. TETRODOTOXIN is found in their liver and ovaries.DNA Copy Number Variations: Stretches of genomic DNA that exist in different multiples between individuals. Many copy number variations have been associated with susceptibility or resistance to disease.Gene Expression Regulation: 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.Diploidy: The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.Mutation Rate: The number of mutations that occur in a specific sequence, GENE, or GENOME over a specified period of time such as years, CELL DIVISIONS, or generations.Defective Viruses: 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.Chromosome Inversion: An aberration in which a chromosomal segment is deleted and reinserted in the same place but turned 180 degrees from its original orientation, so that the gene sequence for the segment is reversed with respect to that of the rest of the chromosome.Untranslated Regions: The parts of the messenger RNA sequence that do not code for product, i.e. the 5' UNTRANSLATED REGIONS and 3' UNTRANSLATED REGIONS.Crosses, Genetic: Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.Likelihood Functions: Functions constructed from a statistical model and a set of observed data which give the probability of that data for various values of the unknown model parameters. Those parameter values that maximize the probability are the maximum likelihood estimates of the parameters.Tandem Repeat Sequences: Copies of DNA sequences which lie adjacent to each other in the same orientation (direct tandem repeats) or in the opposite direction to each other (INVERTED TANDEM REPEATS).Proteome: The protein complement of an organism coded for by its genome.Genomic Islands: 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".Exons: The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.DNA, Fungal: Deoxyribonucleic acid that makes up the genetic material of fungi.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.DNA Repair: The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.Plant Diseases: Diseases of plants.Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Zea mays: A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.RNA: A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)Genetic Techniques: Chromosomal, biochemical, intracellular, and other methods used in the study of genetics.5' Untranslated Regions: The sequence at the 5' end of the messenger RNA that does not code for product. This sequence contains the ribosome binding site and other transcription and translation regulating sequences.Alu Elements: The Alu sequence family (named for the restriction endonuclease cleavage enzyme Alu I) is the most highly repeated interspersed repeat element in humans (over a million copies). It is derived from the 7SL RNA component of the SIGNAL RECOGNITION PARTICLE and contains an RNA polymerase III promoter. Transposition of this element into coding and regulatory regions of genes is responsible for many heritable diseases.Chromatin: The material of CHROMOSOMES. It is a complex of DNA; HISTONES; and nonhistone proteins (CHROMOSOMAL PROTEINS, NON-HISTONE) found within the nucleus of a cell.DNA, Algal: Deoxyribonucleic acid that makes up the genetic material of algae.Genes, Overlapping: Genes whose nucleotide sequences overlap to some degree. The overlapped sequences may involve structural or regulatory genes of eukaryotic or prokaryotic cells.Chromosomes, Mammalian: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of MAMMALS.Endogenous Retroviruses: Retroviruses that have integrated into the germline (PROVIRUSES) that have lost infectious capability but retained the capability to transpose.Genome-Wide Association Study: An analysis comparing the allele frequencies of all available (or a whole GENOME representative set of) polymorphic markers in unrelated patients with a specific symptom or disease condition, and those of healthy controls to identify markers associated with a specific disease or condition.Computer Graphics: The process of pictorial communication, between human and computers, in which the computer input and output have the form of charts, drawings, or other appropriate pictorial representation.Siphoviridae: A family of BACTERIOPHAGES and ARCHAEAL VIRUSES which are characterized by long, non-contractile tails.DNA Methylation: Addition of methyl groups to DNA. DNA methyltransferases (DNA methylases) perform this reaction using S-ADENOSYLMETHIONINE as the methyl group donor.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.

The prokaryotic beta-recombinase catalyzes site-specific recombination in mammalian cells. (1/7812)

The development of new strategies for the in vivo modification of eukaryotic genomes has become an important objective of current research. Site-specific recombination has proven useful, as it allows controlled manipulation of murine, plant, and yeast genomes. Here we provide the first evidence that the prokaryotic site-specific recombinase (beta-recombinase), which catalyzes only intramolecular recombination, is active in eukaryotic environments. beta-Recombinase, encoded by the beta gene of the Gram-positive broad host range plasmid pSM19035, has been functionally expressed in eukaryotic cell lines, demonstrating high avidity for the nuclear compartment and forming a clear speckled pattern when assayed by indirect immunofluorescence. In simian COS-1 cells, transient beta-recombinase expression promoted deletion of a DNA fragment lying between two directly oriented specific recognition/crossing over sequences (six sites) located as an extrachromosomal DNA substrate. The same result was obtained in a recombination-dependent lacZ activation system tested in a cell line that stably expresses the beta-recombinase protein. In stable NIH/3T3 clones bearing different number of copies of the target sequences integrated at distinct chromosomal locations, transient beta-recombinase expression also promoted deletion of the intervening DNA, independently of the insertion position of the target sequences. The utility of this new recombination tool for the manipulation of eukaryotic genomes, used either alone or in combination with the other recombination systems currently in use, is discussed.  (+info)

Comparison of synonymous codon distribution patterns of bacteriophage and host genomes. (2/7812)

Synonymous codon usage patterns of bacteriophage and host genomes were compared. Two indexes, G + C base composition of a gene (fgc) and fraction of translationally optimal codons of the gene (fop), were used in the comparison. Synonymous codon usage data of all the coding sequences on a genome are represented as a cloud of points in the plane of fop vs. fgc. The Escherichia coli coding sequences appear to exhibit two phases, "rising" and "flat" phases. Genes that are essential for survival and are thought to be native are located in the flat phase, while foreign-type genes from prophages and transposons are found in the rising phase with a slope of nearly unity in the fgc vs. fop plot. Synonymous codon distribution patterns of genes from temperate phages P4, P2, N15 and lambda are similar to the pattern of E. coli rising phase genes. In contrast, genes from the virulent phage T7 or T4, for which a phage-encoded DNA polymerase is identified, fall in a linear curve with a slope of nearly zero in the fop vs. fgc plane. These results may suggest that the G + C contents for T7, T4 and E. coli flat phase genes are subject to the directional mutation pressure and are determined by the DNA polymerase used in the replication. There is significant variation in the fop values of the phage genes, suggesting an adjustment to gene expression level. Similar analyses of codon distribution patterns were carried out for Haemophilus influenzae, Bacillus subtilis, Mycobacterium tuberculosis and their phages with complete genomic sequences available.  (+info)

Genomic complexity among strains of the facultative photoheterotrophic bacterium Rhodobacter sphaeroides. (3/7812)

Pulsed-field gel electrophoresis following the use of rare cutting restriction endonucleases together with Southern hybridization, using markers distributed on chromosomes I and II of Rhodobacter sphaeroides 2.4.1, has been used to examine approximately 25 strains of R. sphaeroides in an effort to assess the occurrence of genome complexity in these strains. The results suggest that genome complexity is widespread and is accompanied by substantial genomic heterogeneity.  (+info)

Evolutionary relationships among diverse bacteriophages and prophages: all the world's a phage. (4/7812)

We report DNA and predicted protein sequence similarities, implying homology, among genes of double-stranded DNA (dsDNA) bacteriophages and prophages spanning a broad phylogenetic range of host bacteria. The sequence matches reported here establish genetic connections, not always direct, among the lambdoid phages of Escherichia coli, phage phiC31 of Streptomyces, phages of Mycobacterium, a previously unrecognized cryptic prophage, phiflu, in the Haemophilus influenzae genome, and two small prophage-like elements, phiRv1 and phiRv2, in the genome of Mycobacterium tuberculosis. The results imply that these phage genes, and very possibly all of the dsDNA tailed phages, share common ancestry. We propose a model for the genetic structure and dynamics of the global phage population in which all dsDNA phage genomes are mosaics with access, by horizontal exchange, to a large common genetic pool but in which access to the gene pool is not uniform for all phage.  (+info)

Identification of a ribonuclease H gene in both Mycoplasma genitalium and Mycoplasma pneumoniae by a new method for exhaustive identification of ORFs in the complete genome sequences. (5/7812)

Exhaustive identification of open reading frames in complete genome sequences is a difficult task. It is possible that important genes are missed. In our efforts to reanalyze the intergenic regions of Mycoplasma genitalium and Mycoplasma pneumoniae, we have newly identified a number of new open reading frames (ORFs) in both M. genitalium and M. pneumoniae. The most significant identification was that of a ribonuclease H enzyme in both species which until now has not been identified or assumed absent and interpreted as such. In this paper we discuss the biological importance of RNase H and its evolutionary implication. We also stress the usefulness of our method for identifying new ORFs by reanalyzing intergenic regions of existing ORFs in complete genome sequences.  (+info)

The use of gene clusters to infer functional coupling. (6/7812)

Previously, we presented evidence that it is possible to predict functional coupling between genes based on conservation of gene clusters between genomes. With the rapid increase in the availability of prokaryotic sequence data, it has become possible to verify and apply the technique. In this paper, we extend our characterization of the parameters that determine the utility of the approach, and we generalize the approach in a way that supports detection of common classes of functionally coupled genes (e.g., transport and signal transduction clusters). Now that the analysis includes over 30 complete or nearly complete genomes, it has become clear that this approach will play a significant role in supporting efforts to assign functionality to the remaining uncharacterized genes in sequenced genomes.  (+info)

The tricarboxylic acid cycle of Helicobacter pylori. (7/7812)

The composition and properties of the tricarboxylic acid cycle of the microaerophilic human pathogen Helicobacter pylori were investigated in situ and in cell extracts using [1H]- and [13C]-NMR spectroscopy and spectrophotometry. NMR spectroscopy assays enabled highly specific measurements of some enzyme activities, previously not possible using spectrophotometry, in in situ studies with H. pylori, thus providing the first accurate picture of the complete tricarboxylic acid cycle of the bacterium. The presence, cellular location and kinetic parameters of citrate synthase, aconitase, isocitrate dehydrogenase, alpha-ketoglutarate oxidase, fumarate reductase, fumarase, malate dehydrogenase, and malate synthase activities in H. pylori are described. The absence of other enzyme activities of the cycle, including alpha-ketoglutarate dehydrogenase, succinyl-CoA synthetase, and succinate dehydrogenase also are shown. The H. pylori tricarboxylic acid cycle appears to be a noncyclic, branched pathway, characteristic of anaerobic metabolism, directed towards the production of succinate in the reductive dicarboxylic acid branch and alpha-ketoglutarate in the oxidative tricarboxylic acid branch. Both branches were metabolically linked by the presence of alpha-ketoglutarate oxidase activity. Under the growth conditions employed, H. pylori did not possess an operational glyoxylate bypass, owing to the absence of isocitrate lyase activity; nor a gamma-aminobutyrate shunt, owing to the absence of both gamma-aminobutyrate transaminase and succinic semialdehyde dehydrogenase activities. The catalytic and regulatory properties of the H. pylori tricarboxylic acid cycle enzymes are discussed by comparing their amino acid sequences with those of other, more extensively studied enzymes.  (+info)

Functional insights from structural predictions: analysis of the Escherichia coli genome. (8/7812)

Fold assignments for proteins from the Escherichia coli genome are carried out using BASIC, a profile-profile alignment algorithm, recently tested on fold recognition benchmarks and on the Mycoplasma genitalium genome and PSI BLAST, the newest generation of the de facto standard in homology search algorithms. The fold assignments are followed by automated modeling and the resulting three-dimensional models are analyzed for possible function prediction. Close to 30% of the proteins encoded in the E. coli genome can be recognized as homologous to a protein family with known structure. Most of these homologies (23% of the entire genome) can be recognized both by PSI BLAST and BASIC algorithms, but the latter recognizes an additional 260 homologies. Previous estimates suggested that only 10-15% of E. coli proteins can be characterized this way. This dramatic increase in the number of recognized homologies between E. coli proteins and structurally characterized protein families is partly due to the rapid increase of the database of known protein structures, but mostly it is due to the significant improvement in prediction algorithms. Knowing protein structure adds a new dimension to our understanding of its function and the predictions presented here can be used to predict function for uncharacterized proteins. Several examples, analyzed in more detail in this paper, include the DPS protein protecting DNA from oxidative damage (predicted to be homologous to ferritin with iron ion acting as a reducing agent) and the ahpC/tsa family of proteins, which provides resistance to various oxidating agents (predicted to be homologous to glutathione peroxidase).  (+info)

  • These bacterial genes encode molecules that could yield narrow-spectrum antibiotics, immune system regulators, and neuroactive drugs. (ucsf.edu)
  • This lab bioinformatics program, ClusterFinder, analyzes bacterial genomic data to identify physically clustered groups of genes in a particular genome that together encode enzymes which interact in sequence to produce drug-like small molecules (i.e., biosynthetic gene clusters). (ucsf.edu)
  • The genome includes both the genes (the coding regions ) and the noncoding DNA , as well as the genetic material of the mitochondria and chloroplasts . (readtiger.com)
  • Genome transplantation is an essential enabling step in the field of synthetic genomics as it is a key mechanism by which chemically synthesized chromosomes can be activated into viable living cells. (medgadget.com)
  • Luckily, researchers have a valuable resource on TSRI's Florida campus, where Shen heads the Natural Products Library Initiative, a library consisting of purified natural products, partially pure fractions, crude extracts and bacterial strains collected from all over the globe that are available for screening. (technologynetworks.com)
  • A potential user ('customer') of our sequencing platform asked how to generate reference genomes for his 4 bacterial strains. (wordpress.com)
  • As a test of the success of the genome transplantation, the team used two methods - 2D gel electrophoresis and protein sequencing, to prove that all the expressed proteins were now the ones coded for by the M. mycoides LC chromosome. (medgadget.com)
  • In 1976, Walter Fiers at the University of Ghent (Belgium) was the first to establish the complete nucleotide sequence of a viral RNA-genome ( Bacteriophage MS2 ). (readtiger.com)
  • The researchers screened 2,739 ancient human remains in total, eventually reconstructing eight Salmonella genomes up to 6,500 years old-the oldest reconstructed bacterial genomes to date. (phys.org)
  • The researchers were able to determine that all six Salmonella genomes recovered from herders and farmers are progenitors to a strain that specifically infects humans but is rare today, Paratyphi C. Those ancient Salmonella, however, were probably not yet adapted to humans, and instead infected humans and animals alike, which suggests the cultural practices uniquely associated with the Neolithization process facilitated the emergence of those progenitors and subsequently human-specific disease. (phys.org)
  • These results illuminate what was likely a serious health concern in the past and reveal how this bacterial pathogen evolved over a period of 6,500 years. (phys.org)
  • This highlights an inherent difficulty in the field of ancient pathogen research, as hundreds of human samples are often required to recover just a single microbial genome. (phys.org)
  • Just as a cookbook gives the instructions needed to make a range of meals including a holiday feast or a summer picnic, the human genome contains all the instructions needed to make the full range of human cell types including muscle cells or neurons. (readtiger.com)
  • A new study published in Nature Ecology & Evolution led by Felix M. Key, Alexander Herbig, and Johannes Krause of the Max Planck Institute for the Science of Human History studied human remains excavated across Western Eurasia and reconstructed eight ancient Salmonella enterica genomes-all part of a related group within the much larger diversity of modern S. enterica. (phys.org)
  • Bacterial gene content variation during the course of evolution has been widely acknowledged and its pattern has been actively modeled in recent years. (genetics.org)
  • Gene truncation or gene pseudogenization also plays an important role in shaping bacterial genome content. (genetics.org)
  • Analysis using the new model not only provides more accurate estimates on gene gains/losses (or insertions/deletions), but also reduces any concern of a systematic bias from applying simplified models to bacterial genome evolution. (genetics.org)
  • reported that genomes with truncated homologs might erroneously lead to false inferences of "gene gain" rather than multiple instances of "gene loss. (genetics.org)
  • This will not only yield more accurate estimates of the rates of gene insertions/deletions, but also provide a quantitative view of the effect of truncated genes on rate estimation, which has been understudied in bacterial genome evolution. (genetics.org)
  • The feasibility to introduce targeted mutations into the BAC cloned virus genome was shown by mutation of the immediate-early 1 gene and generation of a mutant virus. (pnas.org)
  • Genome editing is an important technology for bacterial cellular engineering, which is commonly conducted by homologous recombination-based procedures, including gene knockout (disruption), knock-in (insertion), and allelic exchange. (mdpi.com)
  • Apart from these methods, which directly modify the genomic structure, an alternative approach is to conditionally modify the gene expression profile at the posttranscriptional level without altering the genomes. (mdpi.com)
  • Analysis of over 2000 Escherichia coli genomes reveals an E. coli core genome of about 3100 gene families and a total of about 89,000 different gene families. (wikipedia.org)
  • As single-gene comparisons have largely given way to genome comparisons, phylogeny of bacterial genomes have improved in accuracy. (wikipedia.org)
  • Gene acquisition is an ongoing process in many bacterial genomes, contributing to adaptation and ecological diversification. (sciencemag.org)
  • We measured the extent of phylogenetic conflict and alien-gene acquisition within quartets of sequenced genomes. (sciencemag.org)
  • In all but the most reduced bacterial genomes, there is a substantial fraction of genes whose distributions and compositional features indicate that they originated by lateral gene transfer (LGT) ( 1 ). (sciencemag.org)
  • It "is a landmark in biological engineering taking us from moving one gene or a set of genes to the ability to move an intact genome," said Barbara Jasny, deputy editor of the journal Science, which first reported the experiment in this week's issue. (bio-medicine.org)
  • We study the mechanisms responsible of the bacterial genome variability, with a special interest for those involved in exogenous gene acquisition - the horizontal gene transfer. (pasteur.fr)
  • In the present article we review the differential contribution to the evolution of bacterial genomes that processes such as gene modification, gene acquisition and gene loss may have when bacteria colonize different habitats that present characteristic ecological features. (mdpi.com)
  • Reconstructions of the gene set of the shared ancestor of the γ- Proteobacteria provide strong evidence that B. aphidicola genomes are derived from larger genomes through loss of most genes ( 12 , 19 ). (asm.org)
  • Once we have verified that horizontal gene transfer is indeed a common occurrence in chronic bacterial infections, and we expect that to be the case, it opens the door to a realm of promising new directions in the study and treatment of these diseases,' he said. (infectioncontroltoday.com)
  • Models proposed to explain clustering did not take into account the function of the gene products nor the likely presence or absence of a given gene in a genome. (biomedcentral.com)
  • We propose a model accounting specifically for such clustering, and show that indispensability in a genome with frequent gene deletion and insertion leads to the transient clustering of these genes. (biomedcentral.com)
  • The genome has a high coding density (97%) with many overlapping genes and reduced gene length. (semanticscholar.org)
  • Finally, the analysis of 178 Acinetobacter baumannii and 20 Staphylococcus aureus genomes allowed the detection of a significantly higher number of AR genes than the Resfinder gene analyzer and 11 point mutations in target genes known to be associated with AR. (asm.org)
  • This tenet of bacterial genome evolution generally does not extend to obligate intracellular bacteria owing to their reduced contact with other microbes and a predominance of gene deletion over gene transfer. (oup.com)
  • Published Dec. 18, 2017 in Nature Genetics, a team led by researchers at Joint Genome Institute (JGI) and the Howard Hughes Medical Institute at the University of North Carolina at Chapel Hill (UNC) have exploited a catalog of bacterial genomes to identify and characterize candidate genes that aid bacteria in adapting to plant environments, specifically genes involved in bacterial root colonization. (eurekalert.org)
  • Such a task was previously seen as a true tour de force: The chemically synthesised bacterial genome presented eleven years ago by the American genetics pioneer Craig Venter was the result of ten years of work by 20 scientists, according to media reports. (teknoscienze.com)
  • The obligate host-associated bacteria (with the exception of Candidatus Hodgkinia cicadicola) have short and low GC content genomes. (frontiersin.org)
  • Unlike with most obligate endosymbionts, genome reduction has not played a major role in the evolution of the Barbulanympha ectosymbionts. (osti.gov)
  • Buchnera aphidicola , the obligate symbiont of aphids, has an extremely reduced genome, of which about 10% is devoted to the biosynthesis of essential amino acids needed by its hosts. (asm.org)
  • In diverse bacteria, as well as archaea and eukaryotes, a drastic reduction in overall genome size is associated with obligate dependence on a host (e.g., see references 1 , 10 , 17 , and 34 ). (asm.org)
  • In addition to discovering an evolutionary recent and large-scale horizontal phage transfer between coinfecting obligate intracellular bacteria, we demonstrate that "targeted genome capture" can enrich target DNA to alleviate the problem of isolating symbiotic microbes that are difficult to culture or purify from the conglomerate of organisms inside eukaryotes. (oup.com)
  • The researchers found that while only 63.5 percent of TCGA samples analyzed were from tumors, the tumor samples contained 99.9 percent of reads supporting bacterial integration. (nsf.gov)
  • NEW YORK (GenomeWeb) - In a proof-of-principle demonstration that genomes can be assembled from long, noisy nanopore reads alone, researchers at the Ontario Institute for Cancer Research in Toronto and the University of Birmingham in the UK have used data from the Oxford Nanopore MinIon to assemble a bacterial genome into a single contig. (genomeweb.com)
  • Over the years, researchers have proposed several theories to explain the general trend of bacterial genome decay and the relatively small size of bacterial genomes. (wikipedia.org)
  • Researchers have developed several theories to explain the patterns of genome size evolution amongst bacteria. (wikipedia.org)
  • This enables researchers to choose the optimal strategy for completely decoding even the genomes of bacteria with very complex DNA. (admin.ch)
  • Replacing a Genome Boosts Race to Develop Designer Bugs: Study ( Researchers transformed one bacterial s. (bio-medicine.org)
  • The researchers took the genome of a simple, one-celled organism called Mycoplasma mycoides and transplanted it into a close relative, M. capricolum. (bio-medicine.org)
  • The researchers acknowledged that they were not sure how the one genome displaced the other. (bio-medicine.org)
  • To better understand this balance, National Institutes of Health researchers have set out to explore the skin's microbiome, which is all of the DNA, or genomes, of all of the microbes that inhabit human skin. (genome.gov)
  • Our work has laid an essential foundation for researchers who are working to develop new and better strategies for treating and preventing skin diseases," said Julia A. Segre, Ph.D., of the National Human Genome Research Institute (NHGRI), who was the study's senior author. (genome.gov)
  • While Venter's team made an exact copy of a natural genome, the researchers at ETH Zurich radically altered their genome using a computer algorithm. (teknoscienze.com)
  • The researchers screened 2,739 ancient human remains in total, eventually reconstructing eight Salmonella genomes up to 6,500 years old-the oldest reconstructed bacterial genomes to date. (phys.org)
  • The researchers were able to determine that all six Salmonella genomes recovered from herders and farmers are progenitors to a strain that specifically infects humans but is rare today, Paratyphi C. Those ancient Salmonella, however, were probably not yet adapted to humans, and instead infected humans and animals alike, which suggests the cultural practices uniquely associated with the Neolithization process facilitated the emergence of those progenitors and subsequently human-specific disease. (phys.org)
  • Hidden Giants in Forest Soils In Nature Communications, giant virus genomes have been discovered for the first time in a forest soil ecosystem by JGI and University of Massachusetts-Amherst researchers. (doe.gov)
  • This work provides a blueprint for the next generation of rapid microbial identification and full-genome assembly. (nature.com)
  • Using full-genome microarrays for B. aphidicola of the host Schizaphis graminum , we examined transcriptome responses to changes in dietary amino acid content and then verified behavior of individual transcripts using quantitative reverse transcriptase PCR. (asm.org)
  • These findings might help shed light on the evolution of bacterial endosymbionts and on the mechanisms these organisms use to alter the cell cycle of the host in order to reproduce. (innovations-report.com)
  • In addition, we discuss the temporal constraints in the evolution of bacterial genomes, considering bacterial evolution from the perspective of processes of short-sighted evolution and punctual acquisition of evolutionary novelties followed by long stasis periods. (mdpi.com)
  • This book imparts fundamental knowledge on the structure, organization, and evolution of bacterial genomes. (springer.com)
  • In addressing genome evolution of protist ectosymbionts, our data suggest that the ecological pressures influencing the evolution of extracellular symbionts clearly differ from intracellular symbionts and organelles. (osti.gov)
  • One of the best-studied cases of genome reduction is that of the intracellular bacterial symbiont Buchnera aphidicola , which shows a long evolutionary history of strict maternal transmission in its aphid hosts (Insecta: Homoptera: Aphidoidea) ( 18 ). (asm.org)
  • Genome size of Pachypsylla venusta (Hemiptera: Psyllidae) and the ploidy of its bacteriocyte, the symbiotic host cell that harbors intracellular mutualistic bacteria with the smallest cellular genome. (semanticscholar.org)
  • One way to approach this is to build a minimal genome that includes only the genes essential for life. (sciencemag.org)
  • Bacteria with this minimal genome are viable under laboratory conditions. (teknoscienze.com)
  • As a result, the scientists seeded many small modifications into the minimal genome, which in their entirety are, however, impressive: more than a sixth of all of the 800,000 DNA letters in the artificial genome were replaced, compared to the "natural" minimal genome. (teknoscienze.com)
  • The main reason for the relative density of bacterial genomes compared to eukaryotic genomes (especially multicellular eukaryotes) is the presence of noncoding DNA in the form of intergenic regions and introns. (wikipedia.org)
  • These findings add to our understanding of how mutation risk is distributed across bacterial and likely also eukaryotic genomes, owing to their highly conserved replication and repair machinery. (asm.org)
  • The team led by Christian Ahrens - a bioinformatician at Agroscope and a member of the Swiss Institute of Bioinformatics - has now succeeded in revealing the unexpected complexity of bacterial genomes. (admin.ch)
  • We demonstrate a simple and rapid means to ascertain the repeat structure and total size of a bacterial or archaeal genome without the need for assembly by directly analyzing the abundances of distinct k-mers among reads. (igsb.org)
  • The data present a compelling case that LGT occurs in the human somatic genome, and that it could have an important role in cancer and other human diseases associated with mutations. (nsf.gov)
  • Cancer is a disease driven by the accumulation of genomic alterations, including the integration of exogenous DNA into the human somatic genome. (biomedcentral.com)
  • Dynamics of genome rearrangement in bacterial populations. (nih.gov)
  • In this study, the ability to distinguish between these bacterial 'sub-populations' gave Mykrobe an advantage over conventional testing in detecting resistance to second-line TB drugs. (ox.ac.uk)
  • CGMs are preidentified by making comparisons among a relatively small number of completely or nearly completely sequenced genomes and then applied to analyze larger bacterial populations by targeted identification techniques. (asm.org)
  • The Active Bacterial Core surveillance (ABCs) system collects clinical and demographic information about patients with bacterial infections. (cdc.gov)
  • Furthermore, categorization of subjects based on the similarity or dissimilarity of their microbiota into groups by clustering techniques will not only help to reveal the bacterial distribution pattern in the population, but also facilitate our understanding of the underlying causes or the clinical association of specific types of microbial distributions. (biomedcentral.com)
  • Scientists on the Florida campus of The Scripps Research Institute (TSRI) who had previously discovered the prostate cancer-killing compound LNM E1 have now brought the family of LNM molecules even closer to clinical testing by "mining" the information stored in bacteria genomes. (technologynetworks.com)
  • The myxobacteria have very large genomes, relative to other bacteria, e.g. 9-10 million nucleotides except for Anaeromyxobacter and Vulgatibacter. (wikipedia.org)
  • The origin of replication in each genome is approximately at coordinate 1 and the terminus dif sites are approximately midway through each genome, as marked by grey vertical bars. (nih.gov)
  • There is a lack of CMV mutants because due to the large genome size and slow replication kinetics construction of CMV recombinants turned out to be difficult. (pnas.org)
  • It is our working model of a minimal cell, the result of a compromise between small genome size and an experimentally useful replication rate. (geoset.info)
  • Bacterial origins regulate orisome assembly, a nuclei-protein complex assembled on the origin responsible for unwinding the origin and loading all the replication machinery. (wikipedia.org)