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.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

Rapid methods of measuring the effects of an agent in a biological or chemical assay. The assay usually involves some form of automation or a way to conduct multiple assays at the same time using sample arrays.

A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.

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.

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.

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.

The monomeric units from which DNA or RNA polymers are constructed. They consist of a purine or pyrimidine base, a pentose sugar, and a phosphate group. (From King & Stansfield, A Dictionary of Genetics, 4th ed)

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.

The functional hereditary units of BACTERIA.

The relationships of groups of organisms as reflected by their genetic makeup.

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.

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.

Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.

Deoxyribonucleic acid that makes up the genetic material of bacteria.

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).

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 single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.

The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.

The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.

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.

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.

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.

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.

Genotypic differences observed among individuals in a population.

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).

Any method used for determining the location of and relative distances between genes on a chromosome.

Proteins found in any species of bacterium.

Sequential operating programs and data which instruct the functioning of a digital computer.

Preclinical testing of drugs in experimental animals or in vitro for their biological and toxic effects and potential clinical applications.

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)

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.

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.

Biochemical identification of mutational changes in a nucleotide sequence.

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.

The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.

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.

The systematic study of the complete DNA sequences (GENOME) of organisms.

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.

Controlled operation of an apparatus, process, or system by mechanical or electronic devices that take the place of human organs of observation, effort, and decision. (From Webster's Collegiate Dictionary, 1993)

Deoxyribonucleic acid that makes up the genetic material of viruses.

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.

The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.

A multistage process that includes cloning, physical mapping, subcloning, sequencing, and information analysis of an RNA SEQUENCE.

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.

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.

A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.

Ribonucleic acid that makes up the genetic material of viruses.

Large collections of small molecules (molecular weight about 600 or less), of similar or diverse nature which are used for high-throughput screening analysis of the gene function, protein interaction, cellular processing, biochemical pathways, or other chemical interactions.

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 systematic study of the complete complement of proteins (PROTEOME) of organisms.

The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.

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).

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 outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.

Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)

Established cell cultures that have the potential to propagate indefinitely.

Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.

The complete genetic complement contained in a DNA or RNA molecule in a virus.

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).

A genus of HALOBACTERIACEAE distinguished from other genera in the family by the presence of specific derivatives of TGD-2 polar lipids. Haloarcula are found in neutral saline environments such as salt lakes, marine salterns, and saline soils.

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.

The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.

Methods utilizing the principles of MICROFLUIDICS for sample handling, reagent mixing, and separation and detection of specific components in fluids.

Controlled operations of analytic or diagnostic processes, or systems by mechanical or electronic devices.

The functional hereditary units of VIRUSES.

The design or construction of objects greatly reduced in scale.

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.

Variation in a population's DNA sequence that is detected by determining alterations in the conformation of denatured DNA fragments. Denatured DNA fragments are allowed to renature under conditions that prevent the formation of double-stranded DNA and allow secondary structure to form in single stranded fragments. These fragments are then run through polyacrylamide gels to detect variations in the secondary structure that is manifested as an alteration in migration through the gels.

A multistage process that includes the determination of a sequence (protein, carbohydrate, etc.), its fragmentation and analysis, and the interpretation of the resulting sequence information.

The pattern of GENE EXPRESSION at the level of genetic transcription in a specific organism or under specific circumstances in specific cells.

The process of finding chemicals for potential therapeutic use.

Purines attached to a RIBOSE and a phosphate that can polymerize to form DNA and RNA.

Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.

A technology, in which sets of reactions for solution or solid-phase synthesis, is used to create molecular libraries for analysis of compounds on a large scale.

Proteins prepared by recombinant DNA technology.

The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.

The study of fluid channels and chambers of tiny dimensions of tens to hundreds of micrometers and volumes of nanoliters or picoliters. This is of interest in biological MICROCIRCULATION and used in MICROCHEMISTRY and INVESTIGATIVE TECHNIQUES.

Synthetic or natural oligonucleotides used in hybridization studies in order to identify and study specific nucleic acid fragments, e.g., DNA segments near or within a specific gene locus or gene. The probe hybridizes with a specific mRNA, if present. Conventional techniques used for testing for the hybridization product include dot blot assays, Southern blot assays, and DNA:RNA hybrid-specific antibody tests. Conventional labels for the probe include the radioisotope labels 32P and 125I and the chemical label biotin.

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)

An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.

The addition of descriptive information about the function or structure of a molecular sequence to its MOLECULAR SEQUENCE DATA record.

In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.

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.

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.

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).

Databases devoted to knowledge about specific genes and gene products.

The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.

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 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.

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)

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.

That part of the genome that corresponds to the complete complement of EXONS of an organism or cell.

A mutation caused by the substitution of one nucleotide for another. This results in the DNA molecule having a change in a single base pair.

Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.

The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.

A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.

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.

Partial cDNA (DNA, COMPLEMENTARY) sequences that are unique to the cDNAs from which they were derived.

Methods used to determine individuals' specific ALLELES or SNPS (single nucleotide polymorphisms).

A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.

Overlapping of cloned or sequenced DNA to construct a continuous region of a gene, chromosome or genome.

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.

The parts of a macromolecule that directly participate in its specific combination with another molecule.

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

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.

Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.

The deliberate and methodical practice of finding new applications for existing drugs.

The rate dynamics in chemical or physical systems.

Detection of RNA 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 protein complement of an organism coded for by its genome.

Chromosomal, biochemical, intracellular, and other methods used in the study of genetics.

The record of descent or ancestry, particularly of a particular condition or trait, indicating individual family members, their relationships, and their status with respect to the trait or condition.

Proteins found in any species of virus.

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.

Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.

The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.

Ligand-binding assays that measure protein-protein, protein-small molecule, or protein-nucleic acid interactions using a very large set of capturing molecules, i.e., those attached separately on a solid support, to measure the presence or interaction of target molecules in the sample.

A method of detecting gene mutation by mixing PCR-amplified mutant and wild-type DNA followed by denaturation and reannealing. The resultant products are resolved by gel electrophoresis, with single base substitutions detectable under optimal electrophoretic conditions and gel formulations. Large base pair mismatches may also be analyzed by using electron microscopy to visualize heteroduplex regions.

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.

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.

A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.

Proteins obtained from ESCHERICHIA COLI.

Deoxyribonucleic acid that makes up the genetic material of fungi.

Protein factors that promote the exchange of GTP for GDP bound to GTP-BINDING PROTEINS.

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.

Plasmids containing at least one cos (cohesive-end site) of PHAGE LAMBDA. They are used as cloning vehicles.

The portion of an interactive computer program that issues messages to and receives commands from a user.

Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.

The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.

The application of molecular biology to the answering of epidemiological questions. The examination of patterns of changes in DNA to implicate particular carcinogens and the use of molecular markers to predict which individuals are at highest risk for a disease are common examples.

The sum of the weight of all the atoms in a molecule.

A highly-sensitive (in the picomolar range, which is 10,000-fold more sensitive than conventional electrophoresis) and efficient technique that allows separation of PROTEINS; NUCLEIC ACIDS; and CARBOHYDRATES. (Segen, Dictionary of Modern Medicine, 1992)

A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.

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.

A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.

A collective genome representative of the many organisms, primarily microorganisms, existing in a community.

An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.

Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.

Microdevices that combine microfluidics technology with electrical and/or mechanical functions for analyzing very small fluid volumes. They consist of microchannels etched into substrates made of silicon, glass, or polymer using processes similar to photolithography. The test fluids in the channels can then interact with different elements such as electrodes, photodetectors, chemical sensors, pumps, and valves.

A mutation in which a codon is mutated to one directing the incorporation of a different amino acid. This substitution may result in an inactive or unstable product. (From A Dictionary of Genetics, King & Stansfield, 5th ed)

Pyrimidines with a RIBOSE and phosphate attached that can polymerize to form DNA and RNA.

Electrophoresis in which agar or agarose gel is used as the diffusion medium.

Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.

Software designed to store, manipulate, manage, and control data for specific uses.

DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.

Use of various chemical separation and extraction methods, such as SOLID PHASE EXTRACTION; CHROMATOGRAPHY; and SUPERCRITICAL FLUID EXTRACTION; to prepare samples for analytical measurement of components.

The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.

The simultaneous analysis, on a microchip, of multiple samples or targets arranged in an array format.

The genetic complement of a plant (PLANTS) as represented in its DNA.

The genetic complement of a BACTERIA as represented in its DNA.

The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.

INFLAMMATION of any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM. Causes of gastroenteritis are many including genetic, infection, HYPERSENSITIVITY, drug effects, and CANCER.

An actinomycete from which the antibiotics STREPTOMYCIN, grisein, and CANDICIDIN are obtained.

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.

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.

A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.

Genes which regulate or circumscribe the activity of other genes; specifically, genes which code for PROTEINS or RNAs which have GENE EXPRESSION REGULATION functions.

Small uniformly-sized spherical particles, of micrometer dimensions, frequently labeled with radioisotopes or various reagents acting as tags or markers.

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.

Polymers made up of a few (2-20) nucleotides. In molecular genetics, they refer to a short sequence synthesized to match a region where a mutation is known to occur, and then used as a probe (OLIGONUCLEOTIDE PROBES). (Dorland, 28th ed)

Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.

An individual having different alleles at one or more loci regarding a specific character.

Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.

Assaying the products of or monitoring various biochemical processes and reactions in an individual cell.

Substances that reduce the growth or reproduction of BACTERIA.

Enzymes found in many bacteria which catalyze the hydrolysis of the amide bond in the beta-lactam ring. Well known antibiotics destroyed by these enzymes are penicillins and cephalosporins.

Description of pattern of recurrent functions or procedures frequently found in organizational processes, such as notification, decision, and action.

Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).

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.

Deletion of sequences of nucleic acids from the genetic material of an individual.

The systematic study of the structure and function of the complete set of glycans (the glycome) produced in a single organism and identification of all the genes that encode glycoproteins.

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.

The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.

An array of tests used to determine the toxicity of a substance to living systems. These include tests on clinical drugs, foods, and environmental pollutants.

Substances that comprise all matter. Each element is made up of atoms that are identical in number of electrons and protons and in nuclear charge, but may differ in mass or number of neutrons.

The genomic analysis of assemblages of organisms.

The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.

The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.

Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.

Chromatographic techniques in which the mobile phase is a liquid.

The functional hereditary units of FUNGI.

Elements of limited time intervals, contributing to particular results or situations.

Methods used to measure the relative activity of a specific enzyme or its concentration in solution. Typically an enzyme substrate is added to a buffer solution containing enzyme and the rate of conversion of substrate to product is measured under controlled conditions. Many classical enzymatic assay methods involve the use of synthetic colorimetric substrates and measuring the reaction rates using a spectrophotometer.

The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.

Organized activities related to the storage, location, search, and retrieval of information.

Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.

Deoxyribonucleic acid that makes up the genetic material of plants.

Halogenated anti-infective agent that is used against trematode and cestode infestations.

Ribonucleic acid in plants having regulatory and catalytic roles as well as involvement in protein synthesis.

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.

The concentration of a compound needed to reduce population growth of organisms, including eukaryotic cells, by 50% in vitro. Though often expressed to denote in vitro antibacterial activity, it is also used as a benchmark for cytotoxicity to eukaryotic cells in culture.

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.

Databases containing information about PROTEINS such as AMINO ACID SEQUENCE; PROTEIN CONFORMATION; and other properties.

Methods of creating machines and devices.

DNA present in neoplastic tissue.

A group of deoxyribonucleotides (up to 12) in which the phosphate residues of each deoxyribonucleotide act as bridges in forming diester linkages between the deoxyribose moieties.

Diseases of domestic and wild horses of the species Equus caballus.

The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.