Molecular Biotechnology: Principles and Applications - Glick, B., Pasternak, J. 2002

Glossary of Terms

Adaptor (Adaptor) 1. A synthetic double-stranded oligonucleotide with one blunt and one sticky end. Once the adapter is ligated via its blunt end to a target DNA, the latter can be inserted into a suitable vector using its newly acquired sticky end. 2. A synthetic single-stranded oligonucleotide that, upon self-Hybridization, forms sticky ends and an internal restriction endonuclease site. When the adaptor is inserted into a cloning vector, it introduces a new restriction site into the latter.

Adenine, A (Adenine) A purine base complementary to thymine and uracil. One of the nitrogenous bases that make up DNA and RNA.

Activator (Activator) 1. A substance that stimulates the METABOLISM/31.html">Transcription of a specific Gene or Operon. 2. A protein that binds to an operator and accelerates transcription; also referred to as an "activator protein".

Actin (Actin) A protein found in Muscle fibers. It is a component of Actomyosin, the primary contractile muscle protein.

Allele (Allele) One of two (or more) alternative structural forms of a gene.

Allosteric Regulation (Allosteric regulation) The Introduction/15.html">Regulation of enzyme Activity carried out by an effector molecule that binds to a site on the enzyme molecule distinct from the Active Site.

Alginate (Alginate) A polysaccharide synthesized by various Algae and Bacteria; composed of ß-D-mannuronate and a-L-guluronate residues.

Alternative Splicing (Alternative splicing) The joining of exons of a given gene in different combinations to produce distinct mature mRNA molecules.

Aminoacyl-tRNA (Aminoacyl-tRNA) A tRNA molecule with a specific amino acid attached to its 3'-end.

Aminoacyl site, A-site (Aminoacyl site) The region of the ribosome that binds aminoacyl-tRNA during Translation.

Amino acid (Amino acid) The monomeric unit ("building block") of protein molecules.

Amplicon (Amplicon) A plasmid vector derived from Herpes simplex virus type 1.

Anaerobes (Anaerobes) Microorganisms that grow in the absence of oxygen.

Antibiotic (Antibiotic) A substance synthesized by one microorganism that exerts an inhibitory effect on other microorganisms and Cancer Cells.

Antigen (Antigen) A substance perceived by the Organism as foreign, triggering a specific Immune Response—namely, The production of Antibodies.

Anticodon (Anticodon) A triplet of NUCLEOTIDES in a tRNA molecule that is complementary to the nucleotides of a specific codon in an mRNA molecule.

Antiparallel orientation (Antiparallel orientation)

The opposing polarity (5'→3' and 3'→5') of strands in double-stranded nucleic acid molecules.

"Antisense" RNA (Antisense RNA) An RNA sequence complementary to a specific region or the entirety of a target mRNA molecule.

Antisense strand (Antisense chain) 1. The transcribed (coding) strand in a chromosomal DNA molecule. 2. One of the strands in a double-stranded DNA molecule whose nucleotide sequence is complementary to that of the corresponding mRNA.

Antiserum (Antiserum) The liquid component of Blood containing antibodies.

Antibody (Antibody) A protein (immunoglobulin) synthesized by B-lymphocytes in response to The entry of various Antigens into the body, which specifically interacts with them.

Antifreeze protein (Antifreeze protein) An Alanine-rich protein produced in the Liver of certain aquatic organisms that prevents the freezing of Blood Plasma. It has also been found in the cells of certain insects, plants, and bacteria, where it regulates ice crystal formation at low temperatures.

Aptamer (Aptamer) A synthetic polynucleotide that binds to a protein that does not normally interact with Nucleic Acids.

Attenuated vaccine (Attenuated vaccine) A vaccine prepared using microorganisms that have been attenuated in one way or another.

Autologous cells Cells harvested from a given organism, cultured, potentially genetically modified, and reintroduced into the donor organism.

Autosome Any chromosome other than a sex chromosome. Human somatic cells contain 22 pairs of autosomes and one pair of sex Chromosomes.

Autosomal inheritance The inheritance of a trait via genes located on autosomes, independent of sex.

Acyl carrier protein A low-molecular-weight protein component of a larger multi-enzyme complex involved in fatty acid or polyketide Biosynthesis.

Aerobes Microorganisms that grow exclusively in the presence of oxygen.

Arabidopsis thaliana A plant with a very small genome, widely used as a model organism for studying Plant Growth and developmental processes.

Bacmid A shuttle vector based on the AcMNPV genome capable of replicating in both E. coli and insect cells.

Bacteriophage (phage) A virus that infects bacteria.

Bacteriocin A substance synthesized by one microorganism that kills cells of another microorganism.

Biolistics (Microprojectile bombardment) A method for introducing DNA into plant or animal cells or Organelles using tungsten or gold microparticles. DNA is precipitated onto the particles, which are then used to "bombard" the target cells.

G Proteins Membrane-associated proteins that become activated upon interacting with GTP. They play a key role in signal Transduction from Cell-surface receptors to inner membrane-bound Enzymes.

Heat-Shock proteins Proteins synthesized by cells in response to a sudden increase in Temperature.

Single-Cell Protein (SCP) Protein-rich biomass produced by microbial monocultures and utilized as a dietary Supplement in animal feed.

Betaine A low-molecular-weight compound that serves as a methyl group donor in The biosynthesis of Methionine.

cDNA library A collection of cDNA clones synthesized in vitro from mRNA templates derived from a specific tissue or cell population.

Binary vector system

A two-plasmid Agrobacterium system designed for transferring a T-DNA region carrying cloned genes into plant cells. The virulence genes are located on one plasmid, while the inserted T-DNA region resides on another.

Binary fission A form of asexual reproduction and Cell Division used by Prokaryotic Cells, resulting in the splitting of a single cell into roughly two equal-sized daughter cells.

Bioaccumulation The gradual accumulation of a substance (such as DDT) by living organisms within a food chain.

Bioremediation The breakdown or removal of environmental pollutants using living microorganisms.

Biocontrol The Use of living organisms to suppress the growth and proliferation of pathogenic microorganisms.

Biomarker A biological indicator used to assess the progression of a pathological process or the efficacy of a Treatment.

Biomass 1. Total cellular mass produced by the METABOLIC ACTIVITY OF living organisms. 2. Organic matter that can be utilized as a source of energy or chemical compounds.

Bioreactor (fermenter) A vessel or system designed to support a biologically active environment in which biochemical reactions are carried out by living microorganisms, cell extracts, or enzymes. The term often refers specifically to a vessel used for microbial cultivation.

Biotin labeling 1. The covalent attachment of a biotin molecule to another substance. 2. The incorporation of a biotin-conjugated nucleotide into a DNA molecule.

Blotting Transfer of separated molecules from one medium (e.g., a gel) to a solid support (paper, nitrocellulose filter).

Primer walking (Primer-mediated walking) A method for sequencing extended DNA segments (>1 kb) using a primer complementary to the end of a known sequence. Based on data obtained in the first step, a new primer is synthesized that overlaps the end of the sequenced region and is used to determine The nucleotide sequence of the next stretch of cloned DNA. This Procedure is repeated until the entire segment has been sequenced.

Pribnow box A nucleotide sequence in prokaryotes located 10 nucleotides upstream of the Transcription initiation site. It typically consists of 6 nucleotides: TATAAT.

Hogness box A nucleotide sequence in eukaryotes located 25 nucleotides upstream of the transcription initiation site. It typically consists of 8 nucleotides.

Gap The absence of one or more nucleotides in one of the strands of a double-stranded DNA molecule.

Rapid Amplification of cDNA ends, RACE Generation of double-stranded cDNA terminal fragments complementary to the 3'- or 5'-ends of specific mRNA molecules (3'RACE or 5'RACE, respectively).

Vaccination (Preventive immunization) The administration of an antigen into an organism to induce the production of antibodies against a potential infectious agent.

Variable domains Regions of antibody polypeptide chains that have different Amino acid sequences in molecules of different antibodies. They are responsible for the antigen Specificity of the latter.

Vector A self-replicating DNA molecule (such as a bacterial plasmid) used in Genetic Engineering to transfer genes from a donor organism to a recipient organism, as well as for cloning nucleotide sequences.

Western blotting Transfer of protein molecules separated by gel Electrophoresis onto a solid support.

Virion A viral particle.

Virulence A characteristic of a microorganism's pathogenicity.

Helper virus A virulent strain of a virus in the presence of which a defective virus can replicate in a host cell.

Internal ribosomal entry site, IRES An untranslated sequence located downstream of a coding region in a polycistronic mRNA that binds to the small ribosomal subunit and forms an initiation complex.

Generation time The time required for The Cell number in a population of unicellular organisms to double. Also known as doubling time.

Insert A DNA segment integrated into a cloning vector.

Secondary metabolite A substance that is not essential for cell growth or function, but is synthesized during the stationary phase (usually involved in protecting cells or microorganisms from various environmental factors).

Degenerate primers Synthetic oligonucleotides containing different bases at one of their sites; vir genes A group of Ti plasmid genes required for The transfer of T-DNA into a plant cell.

Gamete A haploid reproductive cell of a multicellular organism.

Haploid A term describing an organism (or cell) that possesses a single set of chromosomes.

Haplotype A combination of alleles on a single chromosome of a diploid organism.

Gene A transcribed region of a chromosome encoding a functional protein, tRNA, or rRNA.

Suicide gene

A gene that causes the death of its own cell under certain conditions.

Genetic Code The system by which Genetic information is stored as a nucleotide sequence, in which every three nucleotides (constituting a codon) encode a single amino acid. It consists of 64 codons encoding all 20 Amino Acids and three termination codons.

Genetic polymorphism The presence of two or more allele forms of individual genes.

Candidate gene A structural gene in The Human Genome whose mutation is only hypothetically (pending proof) considered the cause of a specific hereditary disorder.

Target gene 1. A cloned gene. 2. A gene subjected to a specific intervention. 3. A gene of interest to the researcher.

Genetic immunization The induction of an immune response in an organism without administering an antigen, achieved by introducing a gene that encodes the antigen protein into cells.

Ex Vivo Gene therapy The Introduction of a gene (or genes) into isolated patient cells. Following cultivation and transformation, the cells are reintroduced into the patient's body via transfusion, infusion, or injection. This procedure helps correct genetic defects.

In Vivo Gene therapy The introduction of a gene (or genes) directly into a tissue or organ to correct a genetic defect.

Germ line Gene Therapy The introduction of a gene (or genes) into a fertilized egg or an early-stage embryo. The foreign gene becomes incorporated into the nuclei of all cells in the developing organism, including Germ Cells, thereby altering its phenotype.

Antisense therapy In vivo treatment of a genetic disorder by blocking the synthesis

of a protein through the insertion into The Genome of a nucleotide sequence complementary to a specific mRNA.

Somatic cell gene therapy The introduction of a gene into a non-germ cell to correct a genetic defect.

Genome The complete set of genes within the haploid chromosome set of a given organism.

Genome library, gene bank (library) A collection of cloned DNA fragments that collectively represent an individual, group, or species genome. For large genomes (such as those of mammals), chromosome-specific libraries are constructed.

Genotype The genetic makeup of an organism, comprising the full set of its alleles.

Genotyping The determination of all alleles across all loci of a given chromosome.

Genotyping Determination of all alleles of all loci of a given chromosome.

Regulator gene (Regulator gene, repressor gene) A gene that encodes a repressor protein, which binds to the operator and regulates the transcription of its target operon.

Reporter gene A gene encoding an easily detectable product. Such genes are used, for instance, to verify that a specific genetic construct has been successfully introduced into a cell, organ, or tissue.

Housekeeping genes A set of essential structural genes required for the maintenance of basic cellular Functions.

Heterozygote An organism whose genome contains one or more pairs of differing alleles.

Heterologous probe A DNA segment from one organism used to screen a library for similar DNA sequences from another organism.

Heteromeric protein A protein composed of two or more different polypeptide chains (subunits).

Hybridization The annealing of two polynucleotide strands, often from different sources, to form DNA/RNA or DNA/DNA hybrids stabilized by Hydrogen Bonds.

DNA hybridization The pairing of two DNA molecules, often from different sources, through The formation of hydrogen bonds between complementary nucleotides. Used to detect specific nucleotide sequences within a DNA sample.

Fusion protein, chimeric protein The product of two or more coding sequences from different genes that have been cloned together, resulting in a single polypeptide chain.

Hybrid gene, chimeric gene A gene composed of parts from two or more genes, expressed as a single unit to produce a fusion (chimeric) protein.

Hybridoma A hybrid cell line produced by the fusion of normal antibody-producing cells (lymphocytes) with myeloma cells. It possesses the capacity for immortal growth and the synthesis of Monoclonal Antibodies.

3'-hydroxyl group The hydroxyl group attached to the 3'-carbon atom of the sugar residue (ribose or deoxyribose) of the terminal nucleotide in a nucleic acid molecule.

Hypervariable region A site within the variable part of a heavy or light chain of an immunoglobulin molecule, characterized by a much higher degree of Variability in antibodies of different specificities compared to other segments, known as framework regions.

Glycosylation The covalent attachment of a sugar residue to a protein molecule.

β-1,3-glucanase A plant enzyme synthesized by plant cells in response to the invasion of pathogenic Fungi. It hydrolyzes specific Components of the fungal Cell wall and is also produced by certain bacteria.

Homodimeric protein A protein consisting of two identical polypeptide chains (subunits).

Homozygous dominant An organism in which both alleles at a given locus are dominant.

Homozygous recessive

An organism in which both alleles at a given locus are recessive.

Homozygosity The presence of identical alleles at one or more loci. A cell or organism carrying such alleles is called a homozygote.

Homologous chromosomes Chromosomes that contain identical sets of genes arranged in the same relative order. They are formed As a result of the duplication of parental chromosome pairs.

Homologous Originating from a common source or having a similar Structure or evolutionary origin.

Homomeric protein A protein composed of two or more identical polypeptide chains (subunits).

Homopolymer A polymer consisting of identical monomer units.

Incompatibility group A group of Plasmids whose members can coexist within the same cell.

Compatibility group A group of plasmids whose members are unable to coexist within the same bacterial cell.

Guanine, G A purine base complementary to cytosine. One of the four nitrogenous bases found in DNA and RNA.

HUMORAL IMMUNE RESPONSE

The synthesis of antibodies by B cells of The Immune System in response to the presence of foreign antigens in the organism.

Double heterozygote An organism that is heterozygous at two gene loci simultaneously.

Double Crossing-over Crossing-over that occurs simultaneously at two points in a pair of homologous chromosomes.

Dicistronic vector A cloning vector designed for the expression of two genes in a single mammalian cell. The genes are under the control of a single promoter and polyadenylation signal.

Dehalogenation The removal of a halogen atom (chlorine, iodine, bromine, fluorine), typically occurring during biodegradation.

Deoxyribose A five-carbon monosaccharide that is a component of DNA.

Deoxyribozyme A DNA molecule possessing catalytic activity.

Deoxyribonuclease I, DNase I An enzyme that cleaves double-stranded DNA. It is commonly used for purifying RNA preparations and cell-free extracts.

Deoxyribonucleic acid, DNA A polymer composed of deoxynucleotides; a species-specific carrier of genetic information.

Deletion The loss of an internal segment of a chromosome.

Denaturation 1. The Separation of the strands of a double-stranded DNA or RNA molecule. 2. The disruption of the native conformation of biological macromolecules resulting from The breakdown of non-covalent (hydrogen) bonds.

Derepression The induction of GENE TRANSCRIPTION AS a result of the suppression of repressor functions—specifically, blocking its binding to the promoter.

Diazotroph An organism capable of Nitrogen Fixation.

Diaminopimelic acid The direct precursor of L-Lysine in bacteria and plants, and a component of The cell wall in certain bacteria.

Dihydrofolatereductase An enzyme that catalyzes the formation of tetrahydrofolic acid.

Dideoxynucleotide, ddNTP An artificially synthesized nucleoside triphosphate lacking 2'- and 3'-hydroxyl groups on the sugar ring carbon atoms.

Wild type The phenotype most commonly found in natural populations, with traits determined by "normal" (non-mutant) alleles.

Diploid An organism whose cells contain two homologous sets of chromosomes.

Disulphide bond A covalent bond between two sulfur atoms belonging to Cysteine residues. It stabilizes the Tertiary Structure of polypeptide chains.

Dithiothreitol A low-molecular-weight thiol-containing reducing agent. It is added to Buffer solutions at low concentrations to prevent The oxidation of sulfhydryl groups in proteins, and at high concentrations to reduce Disulphide bonds.

Long terminal repeats, LTR

Direct repeat sequences at the ends of the retroviral genome DNA copy.

DNA probe A DNA fragment labeled in a specific way and used for hybridization with a specific region in a DNA molecule. It enables the identification of complementary nucleotide sequences.

DNA ligase An enzyme that catalyzes the formation of a phosphodiester bond between the 3'-hydroxyl group and the 5'-phosphate of adjacent nucleotides at a single-strand break in a DNA molecule.

Sequence tagged site, STS

A locus-specific oligonucleotide that can be used for its identification by PCR.

DNA polymerase An enzyme that catalyzes the synthesis of a polynucleotide chain from individual nucleotides using another strand as a template and a DNA primer with a free 3'-OH group.

Taq DNA polymerase A thermostable DNA polymerase (retaining activity at 95 °C) from the bacterium Thermus aquaticus. Commonly used in PCR.

Sodium dodecyl sulfate An anionic detergent used for Protein Denaturation.

Domain A region of a polypeptide chain that performs a specific function (e.g., cytoplasmic domain, transmembrane domain, etc.).

Dominant gene A gene that manifests itself in the phenotype regardless of the presence of another allele of this gene in the genome.

Dominancy The participation of only one allele in determining a trait in a heterozygous individual.

Vector capacity The maximum size of a DNA insert that can be cloned into a given vector.

Enolase An enzyme that catalyzes The conversion of 2-phosphoglycerate to phosphoenolpyruvate.

Enolreductase An enzyme involved in the synthesis of polyketide Antibiotics.

Founder animal An organism carrying a foreign gene in its germline cells that, upon mating, gives rise to a pure line of transgenic organisms.

Replacement therapy The administration of metabolites, Cofactors, or HORMONES to the body to compensate for a deficiency caused by a genetic defect.

Probe 1. A labeled compound used to detect related biochemical molecules in a complex sample. 2. An oligonucleotide used to identify complementary sequences via hybridization.

Isopropyl-β-D-thiogalactopyranoside, IPTG An inducer of the lac (lactose) operon. In Recombinant DNA technology, it is used to induce cloned genes under the control of the lac repressor–lac promoter system.

Immunotherapeutic procedure The use of an antibody or a chimeric protein containing an antibody-binding site for treating a patient or alleviating their condition.

Immune response The totality of physiological processes in an organism induced by the entry of foreign antigens.

Immunoaffinity Chromatography A purification method in which an antibody immobilized on a matrix binds a specific protein present in a complex mixture of other proteins.

Immunoassay A method based on the ability of an antibody to recognize a specific component in a biological sample.

Screening by immunological assay Screening of a genomic library based on the detection of a target gene product using immunological Methods. It is performed in the absence of a suitable DNA probe.

Immunosuppression The loss of the organism's immune system capacity to mount an Immune Response to a specific antigen.

Immunotoxin A chimeric protein consisting of two domains, one of which has antibody properties and the other acts as a toxin. The first domain

ensures the binding of the chimeric protein to a specific molecule or cell, while the second inactivates the target molecule or kills the cell.

End-product inhibition The inhibition of an enzyme by a metabolite that is the end product of a metabolic pathway.

Indole-3-acetic acid, IAA A plant hormone belonging to the auxin Class that stimulates plant growth.

Inducer (Inductor) A small molecule that binds to a regulatory repressor protein, leading to the derepression of the corresponding genes.

Induction The derepression of a gene or a group of genes under the action of an inducer.

Initiation THE START OF biopolymer synthesis.

Initiation codon An AUG codon within an mRNA molecule encoding methionine (N-formylmethionine in prokaryotes) from which the synthesis of polypeptide chains begins (is initiated). Also known as a Translation initiation signal.

Initiation complex A structure required for the initiation of Polypeptide chain synthesis by Ribosomes. It consists of the small (30S) ribosomal subunit, initiation factors, formylmethionyl-tRNA, GTP, and the mRNA being translated.

Insecticide A substance or living organism that kills insects.

Integration The insertion of foreign DNA (usually via Homologous Recombination) into a host cell chromosome.

Integrating vector A vector specially designed to facilitate the insertion (integration) of cloned DNA into the host cell genome.

Interleukin-2 A lymphokine secreted by certain T lymphocytes that stimulates T-cell proliferation.

Intron A transcribed region of a gene that contains no codons and is excised from the primary transcript during Processing to yield a functional RNA.

Ion channel A transmembrane protein that facilitates The transport of specific ions.

Excision The cutting out of a DNA segment from a chromosome or cloning vector, performed in vivo or in vitro using a specific enzyme.

Bacterial artificial chromosome, BAC A vector system based on the E. coli F-plasmid, used for cloning large DNA sequences (100–300 kb).

Yeast artificial chromosome, YAC A recombinant DNA molecule consisting of a yeast plasmid integrated with yeast centromeric and telomeric chromosomal regions, marker genes, and several Replication origin sites.

P1 artificial chromosome (PAC)

A vector system based on phage P1, used to introduce a vector with a large insert (100–300 kb) into E. coli cells via electroporation.

Human artificial chromosome, HAC A chromosome produced by combining a telomere, a centromere, and human genomic DNA segments.

Candidate gene mapping

A strategy for identifying the gene responsible for a specific disease, based on data regarding the likely product of that gene.

Capsid The protein shell of a virus particle.

Gene mapping The Determination of the relative positions of genes on a chromosome.

Cassette A group of tandemly arranged, closely linked, and functionally related loci. An example is the cassette model of mating types in yeast.

ß-Ketoreductase An enzyme involved in the synthesis of polyketide antibiotics.

Ketosynthase A low-molecular-weight enzyme and one of the components of the complex involved in polyketide synthesis.

B cells Lymphocytes that produce antibodies and originate from Bone Marrow cells.

Germ line cells Cells that progressively develop into Gametes (ranging from primordial germ cells to mature gametes).

Cell line A population of cells maintained in culture through serial passages.

Cell-mediated immune response Immune reactions initiated by cells rather than by antibodies or other humoral factors.

Clone A population of cells or molecules genetically identical to a single ancestral cell or molecule.

Cloning A set of Procedures used to obtain clones. For example, cloning of Multicellular Organisms involves the transfer of somatic cell nuclei into an enucleated fertilized egg.

Gene cloning A set of methods used to obtain cloned DNA, including isolating a target gene from an organism, inserting it into a plasmid (vector), introducing it into a host cell, and achieving multiple replication.

Cloning vector A DNA molecule (such as plasmid or viral DNA) designed to carry a target DNA insert for cloning.

Codon A sequence of three adjacent nucleotides that encodes a specific amino acid. There are 64 possible nucleotide combinations in codons; 61 of these encode 20 amino acids, and 3 serve as nonsense (stop) codons.

Cointegrative vector system A two-plasmid system used to transfer cloned genes into plant cells. The cloning vector carries a T-DNA region containing the cloned gene. Upon introduction into an Agrobacterium cell, it undergoes homologous recombination with a resident "disarmed" (non-oncogenic) Ti plasmid, forming a single plasmid that carries the genetic information required to transfer the modified T-DNA region into The plant cell.

Combinatorial library A library generated by inserting cDNAs of the light and heavy chains of various antibodies into a phage λ-based vector, with one combination per vector.

Competence The ability of bacterial cells to take up transforming DNA (usually a plasmid).

Complement A serum protein complex that constitutes a component of innate Immunity. It participates in The regulation of inflammatory processes, the activation of phagocytosis, and the lytic action on cell membranes. It is activated by interaction with an immune complex.

Complementary DNA, cDNA (Complementary DNA)

A DNA molecule synthesized on an RNA template with the involvement of an RNA-dependent DNA polymerase (Reverse Transcriptase).

Complementary base sequences Polynucleotide sequences that interact with each other in accordance with base-pairing rules: adenine (A) pairs with thymine (T) [or uracil (U) in RNA], and guanine (G) pairs with cytosine (C).

Homopolymeric tail A homopolymer of deoxyribonucleoside monophosphates attached to the 3'-OH ends of both strands of a blunt-ended DNA fragment. The creation of complementary tails [e.g., poly(A) in the inserted DNA fragment and poly(T) in the vector] allows the fragment to be cloned within a recombinant plasmid.

Complementation The restoration of a wild-type phenotype (or a phenotype close to it) when two DNAs with two recessive Mutations in trans-configuration are combined in a single cell.

Concatemeric molecules Long DNA molecules consisting of several tandemly repeated units. The genome of certain phages exists in this form during replication.

Michaelis constant, КМ (Michaelis constant, КМ) A kinetic parameter of an enzymatic reaction, numerically equal to the Substrate Concentration at which the reaction rate is half-maximal. It characterizes the affinity of an enzyme for its substrate. The lower the КМ, the tighter the binding between the substrate and the enzyme.

Constant domain The invariant part of a polypeptide chain (light or heavy) for a given class of IMMUNOGLOBULINS.

Constitutive synthesis The continuous synthesis of RNA or a specific protein occurring within a cell or an entire organism.

Contig A contiguous set of clones spanning a given chromosomal region or an entire chromosome.

Contransfection The introduction of two different DNA molecules into a single Eukaryotic Cell. In the case of baculovirus-based expression systems, it is the procedure of simultaneously introducing a baculovirus and a vector into cultured insect cells.

Single-strand conformational polymorphism, SSCP (Single-strand conformational polymorphism) Differences in the conformation of single-stranded DNAs that differ from one another by as little as a single nucleotide. The analyzed DNAs are subjected to denaturation. The denatured strands adopt different Conformations and migrate at different rates during gel electrophoresis.

Conjugative plasmids Plasmids capable of being transferred from one cell to another during conjugation.

Conjugation A form of sexual process. In bacteria, it is the unidirectional transfer of DNA from one contacting cell to another.

Corepressor A small molecule that binds to an inactive repressor (aporepressor) to form a complex that attaches to the operator and blocks transcription.

Crown gall A plant tumor whose formation is induced by bacteria of the genus Agrobacterium.

Short tandem repeat, STR (Short tandem repeat)

A terminal nucleotide sequence consisting of di-, tri-, or tetranucleotide repeating units.

Cosegregation The phenomenon whereby two traits are inherited together, meaning their genes are not separated during crossing-over.

Cosmid A vector combining The properties of a plasmid vector and a phage λ-based vector. It contains cos sites.

Cosuppression The suppression of the expression of a specific plant gene upon Plant transformation with an additional copy of that gene integrated in the sense orientation.

Cofactor A low-molecular-weight substance required for a specific enzymatic reaction to proceed.

Cofermentation The simultaneous growth of two microorganisms in a single bioreactor.

Crossing-over The mutual exchange of chromosome segments between homologous homologs, based on chromatid breakage and reunion, leading to a new combination of alleles. Also referred to as recombination.

Xenobiotic A compound produced artificially rather than synthesized by a living organism.

Xylose A five-carbon sugar that serves as a major component of hemicellulose.

Culture A population of cells or microorganisms grown under controlled in vitro conditions.

Culture medium A solid or liquid medium used for cultivating microorganisms in vitro.

Cap A methylated guanosine residue at the 5'-end of many eukaryotic mRNAs.

The rate constant of an enzymatic reaction. The higher this value, the faster the substrate is converted into product.

k_cat/K_M The catalytic efficiency of an enzymatic reaction. The higher this value, the faster and more efficiently the substrate is converted into product.

Upstream element A conventional term for the operon region located upstream of the transcription initiation site, in the 5' direction from it. Typically, the first transcribed base of an operon is designated as +1, and all upstream elements are denoted by numbers with a minus sign.

Ligation The joining of two DNA molecules via phosphodiester bonds. In vitro, this process is catalyzed by T4 phage DNA ligase.

Oligonucleotide ligation assay (OLA) A method for detecting single-nucleotide substitutions in a target gene using short oligonucleotides complementary to opposite strands of the test DNA segment. If no substitution is present, both oligonucleotides fully hybridize to the DNA, and upon addition of DNA ligase to the reaction mixture, they are joined (ligated). Otherwise, ligation is impossible.

Lignocellulose A complex of Lignin, hemicellulose, and Cellulose that forms the structural framework of the plant cell wall.

Leader sequence An untranslated mRNA sequence located between the 5'-end and the AUG initiation codon.

Lysis The breakdown of cell walls under the action of enzymes contained in Lysosomes or other agents.

Lysogeny The integration of a bacteriophage genome into the host cell genome. Upon induction, the viral DNA can excise to form mature phage particles.

Linker A synthetic oligonucleotide containing a restriction site. It is used to join vector and cloned DNA, with linkers attached to the ends of the latter via blunt-end ligation.

Lipase An enzyme that hydrolyzes Lipids.

Cohesive ends Mutually complementary single-stranded DNA overhangs at the ends of a double-stranded molecule, generated by staggered cuts in double-stranded DNA.

Lipopolysaccharide A compound containing a lipid linked to a polysaccharide. A major component of the Bacterial cell wall.

Liposome A vesicle enclosed by a single- or double-layer membrane composed of lipid molecules. The hydrophobic regions of these molecules face inward, while the hydrophilic regions face outward. The vesicle interior can contain nucleic acids, drugs, etc., which are delivered to specific targets by the liposome.

Lytic cycle The replication of a virus within a host cell, culminating in cell lysis.

Locus The specific physical position on a chromosome where a gene is located.

Macromolecule A polymer with a molecular weight ranging from several thousand to hundreds of millions of daltons (e.g., proteins, nucleic acids, Polysaccharides).

Macrophage A large WHITE BLOOD CELL capable of phagocytosis.

Expressed sequence tag, EST Short marker sequences characteristic of each human expressed gene. They enable researchers to study the size, diversity, and transcriptional activity of expressed human genes.

Marker gene A gene with a known chromosomal Location that exhibits a clear phenotypic trait (such as Antibiotic Resistance, enzymatic activity, etc.).

Marker peptide A segment of a fusion protein molecule that facilitates protein identification or purification.

Messenger RNA, mRNA An RNA molecule that carries the genetic information specifying the Amino Acid Sequence of a particular protein molecule.

Template strand A DNA strand or other polynucleotide used by DNA polymerase as a template for the synthesis of a complementary strand.

Mesophile Microorganisms capable of growing at temperatures ranging from 20 to 50 °C; the optimal growth temperature is 37 °C.

Meristematic tissue Plant tissue capable of active cell division. In young plants, it is typically located at the tips of roots and shoots.

Metabolism The sum total of Physical and Chemical processes occurring within an organism that sustain its life. The products of metabolism are called metabolites.

Metabolic load The disruption of a host organism's metabolism resulting from the introduction and expression of foreign DNA in its genome.

Methylation The attachment of a methyl group to a macromolecule. For example, DNA Methylation involves The addition of such a group to specific cytosine residues, and occasionally adenine.

Label A radioactive isotope or a Ligand identifiable by biochemical or immunological methods (such as a fluorophore) that binds to a macromolecule, allowing the labeled substance to be detected in a sample.

Replica plating The transfer of microorganism colonies from one Petri dish to another using a velvet stamp while strictly preserving the relative spatial arrangement of the colonies.

Random primer method

A technique for producing labeled DNA probes based on the use of synthetic oligonucleotides containing all possible combinations of six nucleotides, and their hybridization with denatured target DNA. Oligonucleotides complementary to the target pair with it. All four deoxynucleotides (one of which is labeled) are added to the reaction mixture along with an enzyme that catalyzes the synthesis of DNA fragments using the target DNA strands as a template and the hybridized fragments as primers.

Microinjection The introduction of DNA or other molecules into an isolated eukaryotic cell using a fine needle.

Human minisatellite DNA Non-coding human DNA, typically GC-rich, containing tandem repeats of short segments (9–40 bp in length).

Missense mutation A mutation in which a codon encoding a specific amino acid is changed to encode a different amino acid.

Mycelium The vegetative body of a fungus, consisting of fine branching filaments.

Target In the broadest sense, a biological entity (tissue, molecule, cell, microorganism) of interest to the researcher.

Mobilization The transfer of chromosomal genes or non-conjugative plasmids from one bacterial cell to another with the assistance of conjugative plasmids.

Transposable element

A DNA segment capable of changing its position within the genome. Such elements include insertion sequences (IS elements) and Transposons.

Molecular Diagnostics The detection, using molecular biology methods, of a pathogenic microorganism, specific substance, or altered nucleotide sequence responsible for a particular disease.

Monoclonal antibodies Homogeneous antibodies strictly specific to a single epitope (antigenic determinant). They are synthesized by hybridomas—cellular hybrids produced by fusing normal antibody-producing cells with a myeloma tumor cell capable of unlimited growth. Some myeloma cells synthesize monoclonal antibodies on their own.

Multipoint map, multilocus linkage map A diagram showing the relative positions of loci on the chromosomes of a given organism.

Мутагенез (Mutagenesis) The artificial introduction of mutations using physical or chemical agents.

Мутант (Mutant) An organism altered as a result of mutation; typically differs from the original form (wild type).

Мутация (Mutation) A spontaneous or induced change in gene structure.

Мутация со сдвигом рамки (Frameshift mutation) A mutation caused by the addition or loss of one or more nucleotides (in a number not a multiple of three). This disrupts the triplet code and leads to the synthesis of an entirely different protein (unless translation is blocked altogether).

Нарушение комплементарности (Mismatch, misparing) The presence of one or more non-complementary Base Pairs within a double-stranded DNA molecule.

Негативная регуляция (Negative control) A type of regulation in which gene transcription is inhibited by a regulatory protein (repressor); accordingly, upon inactivation of the repressor protein, structural genes remain active.

Независимое распределение генов (Independent assortment) The distribution of genes located on different chromosomes into haploid gametes, resulting in all possible gene combinations. It forms The basis of Mendel's law of independent assortment.

Неметаболизирующиеся Индукторы (Gratuitous Inducers) Substances that induce the synthesis of inducible enzymes but do not serve as substrates for them, thus remaining unchanged.

Неомицинфосфотрансфераза (Neomycinphospliotransferase) An enzyme that inactivates the antibiotics neomycin and kanamycin. It is frequently used as a selectable marker for Transgenic Plants.

Неполная пенетрантность (Incomplete penetrance) The partial expression of a specific allele within a group of related organisms. This is characteristic of most mutant alleles.

Непрерывная ферментация (Continuous Fermentation) The CULTIVATION OF MICROORGANISMS involving the continuous addition of medium to a bioreactor and the withdrawal of an equivalent volume of suspension.

Нозерн-блоттинг (Nothern blotting) The transfer of electrophoresed RNA molecules from a gel to a solid support (nitrocellulose or nylon filter) followed by DNA-RNA hybridization.

«Нокаут» (Knockout) The targeted disruption of a gene via homologous recombination.

Нуклеаза S1 (S1 nuclease) An enzyme that specifically degrades single-stranded DNA.

Нуклеозцд (Nucleoside) A purine or pyrimidine nitrogenous base covalently linked to a five-carbon sugar (pentose). If the sugar is ribose, it is a ribonucleoside; if it is deoxyribose, it is a deoxyribonucleoside.

Нуклеотид (Nucleotide) A nucleoside with one or more phosphate groups attached to the 5'-carbon atom of the sugar ring. Nucleosides linked to ribose are called ribonucleoside monophosphates (rNMP), ribonucleoside diphosphates (rNDP), or ribonucleoside triphosphates (rNTP). For nucleosides linked to deoxyribose, the corresponding terms are deoxyribonucleoside mono-, di-, and triphosphates (dNMP, dNDP, dNTP).

N-конец (N terminus) The first amino acid (or several amino acids) in a protein molecule.

Обратная транскриптаза (Reverse transcriptase) An RNA-dependent DNA polymerase that uses an RNA molecule as a template to synthesize a complementary DNA strand.

Обратная Транскрипция—Полимеразная цепная реакция (Reverse transcription—Polymerase Chain Reaction) A method for producing large quantities of cDNA in two steps. First, cDNA is synthesized in vitro using reverse transcriptase, mRNA as a template, and an oligo(dT) primer. Second, the cDNA is amplified via the polymerase chain reaction (PCR) using two primers: one complementary to a region of the first cDNA strand, and the other to the strand complementary to the first.

Одноцепочечный разрыв (Nick) A break in the phosphodiester bond between adjacent nucleotides in a single DNA strand.

Окрашивание по Граму (Gram stain) A staining technique for microbiological specimens that distinguishes between two groups of bacteria: Gram-positive and Gram-negative. It is based on differences in the Biochemical Composition of bacterial cell walls.

Олигонуклеотид, олигомер (Oligonucleotide) A short (6–10 nucleotides) single-stranded DNA segment. Usually produced chemically.

Онкоген (Oncogene) A gene whose expression leads to uncontrolled cell proliferation (transformation).

Оператор (Operator) A DNA segment adjacent to a structural gene that regulates its transcription with the participation of a repressor or activator.

Оперон (Operon) A DNA segment containing multiple structural genes transcribed to form a single polycistronic mRNA.

Opine A Condensation product of an amino acid with a keto acid and a sugar.

Codon optimization The modification of codons in a given gene without altering The amino acid sequence of the encoded protein, aimed at ensuring efficient translation by the host organism.

Annealing The process by which double-stranded molecules (DNA–DNA or DNA–RNA) are formed from single complementary polynucleotide strands.

Open Reading Frame A nucleotide sequence that contains no termination codons and encodes a polypeptide or protein.

DNA fingerprint A set of DNA Restriction fragments characteristic of a particular individual. Fingerprinting is performed using either gel electrophoresis alone or in combination with PCR amplification.

Repulsion A configuration in which two mutant non-allelic genes are located on different chromosomes. Equivalent to the trans-configuration. See also Linkage.

Packaging cell line A cell line engineered to produce Viral Particles that lack infectious nucleic acid.

Palindrome A segment of a double-stranded DNA molecule in which both strands have the same nucleotide sequence when read from the 5' to the 3' end. Such regions are frequently recognized by type II Restriction Endonucleases.

Parasporal crystal Tightly packed toxin molecules synthesized by Bacillus thuringiensis during spore formation.

Passive immunity A form of immunity acquired by introducing into an organism serum containing antibodies produced by another organism as a result of active immunization. Also observed in newborns.

Pathogenesis-related promoter A plant gene promoter that is activated when the plant is infected by pathogens.

Penetrance The frequency of expression of a given allele within a group of related organisms. Complete penetrance means the allele is expressed in every member of the population.

Peptide A short chain of amino acids linked by peptide bonds.

Peptidyl-tRNA A tRNA molecule with a growing polypeptide chain attached to it.

Peptide vaccine A short chain of amino acids that induces the production of antibodies against a specific infectious agent.

Peptide bond A covalent bond between the free carboxyl group at the a-carbon atom of one Amino Acid and the free amino group at the same carbon atom of an adjacent amino acid in a polypeptide chain.

Primary culture A culture of cells or Tissues taken directly from an organism.

Primary transcript An RNA molecule transcribed from a eukaryotic structural gene that has not yet undergone processing (i.e., containing all exons and introns).

Primary antibody An antibody that binds to a target molecule during an immunoassay (e.g., using ELISA).

Batch fermentation The cultivation of microorganisms over a limited time interval. Fresh medium is inoculated with a starter culture, and the process proceeds without the addition of new medium or the removal of products until it runs its course.

Fed-batch fermentation The cultivation of microorganisms over a limited time interval with the periodic addition of substrate and harvesting of the product only upon completion of the process.

Periplasmic space The space between The Plasma Membrane of a bacterial cell and its outer membrane or cell wall.

Pyrimidine One of the Two Types of nitrogenous bases found in nucleic acids; Pyrimidines include thymine, cytosine, and uracil. The second type of bases is Purines, which include adenine and guanine.

Pyrogen A substance produced by bacteria that induces fever in humans.

Plasmid An extrachromosomal genetic element capable of autonomous replication and stable maintenance. Typically, it is a double-stranded circular DNA molecule 1–200 kb in length.

Helper plasmid A plasmid that supplements the functions of another plasmid within the same cell. Some helper plasmids facilitate the transfer of non-conjugative plasmids from a donor cell to a recipient cell.

2 μm plasmid A naturally occurring double-stranded circular plasmid with a length of 6318 bp, discovered in The Nucleus of Saccharomyces cerevisiae. It has served as the basis for numerous Plasmid Vectors designed for yeast cells.

Plasmid incompatibility A mechanism that regulates the copy number of plasmids of the same type within a bacterial cell, preventing the intracellular coexistence of plasmids belonging to the same compatibility group.

Plasmovirus A genetic construct containing retroviral genes under the control of a 5'-LTR promoter, as well as a therapeutic gene and an env gene driven by a cytomegalovirus promoter.

Plastid An organelle found in plant cells (e.g., a chloroplast). Many Plastids possess their own genome.

Subspecies A group within a species characterized by traits not typical of the rest of the population members of that species.

Positive control A type of regulation in which a regulated gene is transcribed only in the presence of an activator protein.

Positive-negative Selection A technique that simultaneously selects for cells carrying an insertion at a specific chromosomal site (positive selection) while counter-selecting against cells carrying an insertion at a different, non-specific site.

Positive selection The selection of cells based on the presence of a marker gene that confers a growth advantage on a selective medium (e.g., a medium containing an antibiotic).

Positional gene cloning One of the strategies used to identify a disease-related gene in the absence of data regarding its protein product or any candidate genes. In such cases, the chromosomal location (position) of the gene is determined first. Genomic clones spanning the mapped site are then obtained using appropriate markers, and the exons present within them are identified and analyzed. Employing a range of methods—such as GC-island identification, exon trapping, sequencing, and computational analysis—researchers determine which specific gene is responsible for the given disease.

Positional-candidate gene cloning One of the strategies for identifying a disease-related gene when data on its protein product are lacking, but the gene has been mapped to the same chromosomal region as already identified genes and ESTs. Current genetic and transcriptional maps are first analyzed to identify coding sequences (genes, intragenic ESTs) located in that region; subsequently, mutation analysis or other methods are used to pinpoint the exons associated with the disease.

Polyadenylation The enzymatic addition of adenine residues to the 3'-end of a eukaryotic mRNA molecule. This adenine-rich 3'-end is referred to as the poly(A) tail.

Multivalent vaccine A vaccine that elicits an immune response against multiple infectious agents or against different epitopes of a single molecule.

Polyketide synthase An enzyme involved in the biosynthesis of polyketide antibiotics.

Polyketide antibiotics A class of antibiotics produced through the sequential enzymatic condensation of carboxylic acids (such as acetate, propionate, etc.).

Polylinker A short DNA segment containing several unique restriction endonuclease recognition sites into which foreign DNA is inserted during cloning procedures.

Polymerase chain reaction, PCR A method for the amplification of a specific DNA segment using a thermostable DNA polymerase and oligonucleotide DNA probes complementary to the sequences on opposite DNA strands that flank the amplified segment. The process consists of a series of cyclically repeated reactions: DNA denaturation, probe annealing, and DNA Synthesis.

Restriction fragment length polymorphism, RFLP The variability in the length of DNA fragments generated by restriction endonuclease Digestion. It is caused by mutations that alter existing restriction sites or create new ones, and is detected by separating the fragments via gel electrophoresis.

Short tandem repeat polymorphism, STRP The variability in the number of repeating units within blocks of tandem di-, tri-, or tetranucleotide repeat elements, with a population frequency of at least 1%. STRP loci are detected by gel electrophoresis following PCR amplification using primers complementary to unique sequences flanking the locus.

Polymorphic site A chromosomal region represented in a population by more than one variant, occurring at a frequency of at least 1%.

Polynucleotide A linear polymer consisting of 20 or more nucleotides linked together by phosphodiester bonds. DNA and RNA molecules are Examples of polynucleotides.

Polypeptide A linear polymer consisting of amino acids linked together by peptide bonds. A protein molecule is an example of a polypeptide.

Multigene RNA, polysistronic message An mRNA molecule that encodes more than one protein. It is formed during the transcription of two or more adjacent genes belonging to the same operon.

Polyhedrin The capsid protein of Baculoviruses, which accumulates in large quantities within the nuclei of infected insect cells.

Complete linkage The joint inheritance of two or more adjacent gene loci on a chromosome. It is manifested by the absence of recombination between them and their stable co-segregation into the same gamete during mitosis.

Posttranslational modifications (Posttranslational modifications) Alteration of protein molecule structure following the completion of their synthesis by ribosomes. Such modifications include phosphorylation, glycosylation, cysteine oxidation, Cleavage of signal Peptides, etc.

Downstream element (Downstream) A conventional term for a region located downstream of the transcription initiation site, in the 3’ direction from it.

Primer (Primer) A short oligonucleotide that hybridizes with a template and serves as a starting point (primer) for its replication.

Immediate-early gene (Immediate-early gene) A phage gene transcribed immediately upon cell infection. Its product is required for the transcription of other bacteriophage genes, namely the delayed-early and late genes.

Chromosome walking (Chromosome walking) A method for identifying nucleotide sequences flanking known genes for which oligonucleotide probes are available. The flanking sequences are subsequently used as probes to identify adjacent sequences, and so forth.

Human Genome Project (Human Genome Project) An international initiative aimed at mapping the human genome genetically and physically and determining its complete DNA nucleotide sequence.

Prokaryotes (Procaryotes) Organisms that lack membrane-bound nuclei and organelles. Prokaryotes include all bacteria.

Promoter (Promoter) A region of a DNA molecule to which RNA polymerase binds, initiating Transcription of the corresponding genes. It is typically located upstream of the 5'-end of the regulated gene.

Proteases, Proteolytic Enzymes (Protease) Enzymes that cleave peptide bonds in protein molecules.

Proteolysis (Proteolysis) The enzymatic Breakdown of Proteins.

Protoplast (Protoplast) A bacterial, yeast, or plant cell whose cell wall has been removed enzymatically or chemically.

Prophage (Prophage) Bacteriophage DNA integrated into the genome of a host bacterial cell and replicating along with it.

Processing. The set of cellular processes leading to the formation of mature RNA and Protein molecules. It involves a series of successive cleavages of a precursor molecule by endonucleases or proteinases.

Readthrough. The continuation of transcription past a specific terminator. A similar term is also used in the context of translation.

Chromosome jumping. A variation of chromosome walking characterized by the shifting (jumping) of a screening marker gene due to a mutation, which makes it possible to identify new linked genes.

Psychrophiles (Psychrophile). Microorganisms capable of growing at temperatures of 0–5 °C.

Purines (Purine). One of the two types of nitrogenous bases found in nucleic acids, which includes adenine and guanine. The second type of bases is pyrimidines, which include thymine, uracil, and cytosine.

Pseudomonas is a widespread genus of Gram-negative bacteria. Many soil-dwelling species produce a pigment that fluoresces under UV light.

Reading frame. One of the three possible ways of reading a nucleotide sequence as triplets. An open reading frame contains no termination codons and can be translated into a protein.

Map distance. The distance between two genes, determined by the recombination frequency in the region being analyzed. The mapping unit is defined as the distance between genes with a recombination probability of 1% (one centimorgan).

Stirred tank fermenter. A bioreactor that uses mechanical agitators to ensure the uniform distribution of gas throughout the medium.

Regulatory protein. A protein that "turns on" or "turns off" transcription.

Recombinant DNA. A DNA molecule formed by the in vitro joining of heterologous DNA fragments that do not naturally occur together.

Recombinant plasmid. A plasmid modified using genetic engineering techniques. It consists of regions from different plasmids or contains DNA segments from other organisms.

Recombinant protein. A protein encoded by cloned recombinant DNA.

Ренатурация (Renaturation) The reassociation of complementary strands of a double-stranded DNA molecule that have been separated by denaturation.

Репликативная форма, РФ (Replicative form) An intermediate form of a double-stranded viral nucleic acid that serves as a template for DNA and RNA Synthesis. It typically appears as a relaxed (open) circle.

Репликация (Replication, reduplication) The process of self-replication (synthesis) of DNA.

Репликация по типу катящегося кольца (Rolling circle model) A process of circular DNA replication that generates concatemeric duplex DNA (DNA consisting of multiple tandemly repeated genome units).

Репрессия (Repression) One of two alternative gene regulation mechanisms (along with induction). It involves the suppression of transcription or translation through the binding of a repressor protein to an operator.

Репрессор (Repressor) A protein that binds to the operator or promoter of a given gene, thereby blocking the binding of RNA polymerase to these elements.

Рестриктаза, рестрицирующая эндонуклеаза (Restriction endonuclease) A bacterial enzyme that cleaves double-stranded DNA molecules at specific recognition sites.

Рестрикционная карта (Restriction шар) A diagram mapping the positions of restriction enzyme cleavage sites on a DNA molecule.

Ретровирусы (Retroviruses) A group of RNA Viruses containing reverse transcriptase; the double-stranded DNA synthesized on the RNA template can integrate into the host cell's chromosome.

Рецессивный аллель (ген) [Recessive allele (gene)] An allele that encodes a trait expressed only in individuals that are homozygous for this allele.

Рибоза (Ribose) A five-carbon monosaccharide (pentose) that is a structural component of RNA.

Рибозим (Ribozyme) An RNA molecule with catalytic (enzymatic) activity.

Рибонуклеиновая кислота, РНК (Ribonucleic acid, RNA) A nucleic acid composed of ribonucleotides, containing ribose as the sugar and uracil instead of thymine as one of the pyrimidine bases.

Рибосома (Ribosome) A cellular organelle, specifically a ribonucleoprotein particle, that serves as the site of Protein Synthesis (translation). It consists of a large and a small subunit.

Рибосомная РНК, рРНК (Ribosonial RNA, rRNA) The RNA component of ribosomes.

Рибулозо-1,5-бисфосфат—карбоксилаза (Ribulozo bis-phosphate carboxylase) The most abundant enzyme in the tissues of all green plants, responsible for carbon dioxide fixation during the initial Stages of Photosynthesis.

Ризосфера (Rhizosphere) The narrow zone of soil directly surrounding plant roots, characterized by a high concentration of microorganisms.

РНК-полимераза (RNA polymerase, RNA synthetase)

Фермент, осуществляющий Синтез РНК из рибонуклеозидтрифосфатов. Матрицей может служить ДНК или РНК, соответствующие РНК-полимеразы называют ДНК- или РНК-зависимыми.

Rec А Бактериальный белок, участвующий в рекомбинации и репарации ДНК.

Rhizobium Вездесущие Бактерии, обитающие в корнях растений или в примыкающем к ним слое почвы.

Сайт встраивания (клонирования) (Cloning site) A specific region within a vector molecule where a foreign DNA fragment can be inserted. This is very commonly a unique restriction site.

Сайт рестрикции (Restriction site) A specific nucleotide sequence in a DNA molecule recognized by a restriction endonuclease. It typically consists of a short palindrome.

Сайт-специфический мутагенез (Site-specific mutagenesis) The introduction of an in vitro mutation into a specific site of a cloned sequence. This technique allows researchers to identify functional regions in protein molecules and engineer proteins with predetermined properties. Sometimes referred to as oligonucleotide-directed mutagenesis.

Самореплицирующийся элемент (Self-replicating element) An extrachromosomal nucleic acid molecule capable of independent (autonomous) replication, separate from chromosomal DNA. Plasmids serve as a classic example of such an element.

Centimorgan, cM (Centimorgan) A unit of measurement for distance on a genetic map. 1 cM corresponds to the distance between genes that undergo recombination with a frequency of 1%. For Human chromosomes, 1 cM is approximately equal to 10⁶ bp. This unit was introduced by T. Morgan during his experiments studying genetic linkage in Drosophila.

Southern blotting (Southern blotting) The detection of specific nucleotide sequences by transferring electrophoresed, denatured DNA molecules from an agarose gel to a nitrocellulose or nylon filter via capillary action, followed by hybridization with a labeled probe complementary to the target sequence.

Sequencing gel (Sequencing gel) A long polyacrylamide gel slab used for the electrophoretic separation of oligo- and polynucleotides that differ in length by as little as 1 nucleotide.

Secretion (Secretion) The release of substances from a cell into the external environment.

Selection (Selection) 1. The science of methods for creating new cultivated plant varieties and animal breeds. 2. The isolation of desired organisms (cells) from a mixed population.

CEPH (Centre d'Etude de Polymorphisme Humain) The Centre for The Study of Human Polymorphism, located in Paris. It maintains a database on the genetic and molecular-genetic variability of human populations from most Regions of the globe.

Serotype (Serotype) The antigenic characteristic of a cell (bacterium, blood cell, etc.) determined by its interaction with antibodies.

Siblings (Sibses) Direct offspring of the same parents (brothers and/or sisters).

Sigma factor (Sigma factor) A bacterial protein that ensures the recognition of a promoter binding site on the DNA molecule by RNA polymerase and the initiation of transcription.

Polyadenylation signal (Polyadenylation sygnał) A nucleotide sequence responsible for the termination of transcription and the determination of the enzymatic addition of adenine residues to the 3'-end of an mRNA molecule.

Signal sequence (Signal region, initiator element) A nucleotide sequence within a gene that serves as a binding site for a protein (transcription factor) that regulates transcription.

Signal peptide, signal sequence, leader peptide (Signal peptide) An N-terminal region of a protein molecule, 15–30 amino acids long, responsible for protein secretion (transmembrane transport). After secretion, this region is cleaved from the protein molecule.

Siderophore (Siderophore) A low-molecular-weight compound that efficiently binds iron. It is synthesized by many soil microorganisms, supplying them with iron, which is subsequently delivered to plants that are in a symbiotic relationship with these microorganisms.

Symbiosis (Symbiosis) The coexistence of different organisms in which each performs its own functions. In some cases, it is mutually beneficial.

Syndrome (Syndrome) A set of symptoms (signs) characteristic of a particular disease.

Complement system (Complement cascade) A series of sequential complement activation processes (a complex blood serum protein complex) and enzymatic reactions triggered in response to the formation of an antigen–antibody complex.

Crossing (Gross, crossing, mating) A single cross between genetically distinct organisms.

Screening (Screening) A method (or set of methods) for identifying a single object (an individual in a population, a cell with desired properties, a nucleotide sequence region, etc.) by examining A large number of objects.

Somatic cell (Somatic cell) Any non-germ cell of a multicellular organism.

Coupling (Coupling) A configuration in which two dominant or two recessive forms of two different genes are located on the same chromosome. Analogous to the cis-configuration. See also Repulsion.

Splicing (Splicing) The excision of introns from an mRNA precursor and the covalent joining of exons to form mature mRNA molecules.

Steady state (Steady state) A continuous fermentation state in which the number of cells removed from the fermenter equals the number entering it.

Stem cells (Stem cells) Mitotically active stem cells whose division replaces dead cells in a multicellular organism.

Structural gene (Structural gene) A gene that encodes a specific protein.

Staggered cut (Staggered cut) The cleavage of double-stranded DNA in which the breaks in complementary strands are not directly opposite each other, but are slightly offset.

Subcloning Transfer of a portion of an already cloned DNA molecule into another cloning vector.

Substrate Substance whose transformation is catalyzed by a specific enzyme.

Subtilisin Proteolytic enzyme synthesized by Bacillus subtilis cells.

Subunit vaccine Vaccine containing only specific components of a pathogenic microorganism.

Suppression Restoration of a lost genetic function caused by the suppression of The Effect of one mutation by the action of a second.

Linkage Interdependent transmission from Cell to Cell of genes localized on the same chromosome.

CpG islands, HpaII tiny fragments CG-rich sequences up to several hundred pairs in size; they flank the 5'-end of many transcribed vertebrate genes and contain restriction sites for HpaII.

Cos-sites Nucleotide sequences at the ends of phage K genome required for DNA packaging into phage particles.

Tandem array Nucleotide sequence consisting of several identical elements connected in a HEAD-to-tail fashion.

TATA box A region located in the promoter region of eukaryotic genes 25 nucleotides upstream of the transcription initiation site, to which RNA polymerase binds. Also known as the Hogness box. The prokaryotic analog is the Pribnow box.

T-DNA A fragment of the Ti plasmid that integrates into the host cell's nuclear DNA and is stably inherited by it. It causes crown gall tumor formation in plants.

Inclusion bodies Small particles of crystallized protein produced in excess within a bacterial cell upon viral infection or upon insertion of the viral genome into the host cell DNA. Their presence indicates pathological Changes in the cell.

Melting temperature, T_m The temperature at which half of the hydrogen bonds in a polynucleotide duplex break.

Terminal transferase (Terminal transferase, deoxynucleotidyl transferase) An enzyme that catalyzes the addition of deoxynucleoside monophosphates to the 3'-end of a DNA molecule. Used for cDNA cloning using complementary homopolymeric tails [poly(A) — poly(T)].

Termination Cessation of macromolecule synthesis.

Terminating codon A codon that signals the end (termination) of polypeptide chain synthesis. These are typically the UAA, UAG, and UGA codons.

Thermophilic Characterizing heat-loving organisms that typically grow at temperatures above 50 °C. Some thermophilic organisms can grow at temperatures from 90 to 100 °C.

Thymidylate synthase An enzyme that catalyzes the methylation of uracil, converting it into thymine.

Thymine, T Pyrimidine base; one of the four nitrogenous bases comprising DNA.

Tissue plasminogen activator A protein involved in the breakdown of blood clots.

T cells Lymphocytes that play a key role in the immune response.

T_H-lymphocytes, helper cells

T lymphocytes that play a primary role in recognizing foreign antigens.

Transgenic organism An organism whose genome contains foreign genetic material introduced by Genetic engineering METHODS.

Transgenesis Introduction of a foreign gene into a plant or animal cell and its transmission across generations.

Transduction The transfer of genetic material from one bacterial cell to another via a bacteriophage.

Transcript An RNA molecule synthesized using a specific DNA strand as a template.

Transcription mapping The assignment of individual transcripts (cDNA clones or targeted expressed sequences) to chromosomal regions using fluorescence in situ hybridization (FISH), PCR, etc.

Transcription The process of RNA synthesis catalyzed by RNA polymerase, in which one of the DNA strands serves as a template.

Translocation 1. A chromosomal rearrangement involving the transfer of a chromosomal segment to a new position on the same or another chromosome, or the transfer of an entire chromosome to another chromosome. 2. The movement of an mRNA molecule along a ribosome by one codon during translation.

Translation The synthesis of a polypeptide chain by a ribosome using mRNA as a template.

In vitro translation Protein synthesis carried out either on purified DNA using bacterial extracts, or on mRNA using wheat germ or rabbit reticulocyte extracts. These extracts contain ribosomes, tRNA, and protein factors; ATP, GTP, and Amino acids are also added to the reaction mixture.

Transposase An enzyme involved in transposition—the movement of certain Mobile Genetic Elements from one site to another.

Transposition The movement of a mobile genetic element from one locus to another.

Transposons Mobile genetic elements carrying structural genes that determine functions unrelated to the transposition process itself (e.g., antibiotic resistance genes).

Transfer RNA, tRNA An RNA molecule that acts as an adaptor in the specific transfer of amino acids to the growing polypeptide chain during translation.

Transfection The artificial introduction of isolated DNA molecules into Eukaryotic cells.

Transformation 1. The transfer of genetic information into bacterial cells with or without plasmids, but always without the involvement of viruses; often resulting in A change in the recipient cell's phenotype. 2. The conversion of normal animal cells into tumor cells.

Trichloroacetic acid, TCA An organic compound frequently used to precipitate proteins and nucleic acids.

Blunt end The terminus of a double-stranded DNA molecule in which neither strand protrudes.

Ti plasmid A plasmid from the soil bacterium Agrobacterium tumefaciens, whose T-region is capable of integrating into host nuclear DNA, leading to tumor formation.

Ty element A mobile genetic element of yeast (derived from transposon of yeast).

Exon trapping A method for identifying and cloning exons from genomic clones. Genomic DNA fragments (1–6 kb) are inserted into a vector polylinker located within an intron flanked by two exons. E. coli cells are transfected with the resulting artificial gene (exon 1–intron–exon 2), where transcription and mRNA splicing take place. If an exon is present within the intron, the mature mRNA will be longer than expected. This mRNA can then be reverse-transcribed, amplified by PCR, and the exon isolated.

Uracil, U A pyrimidine base; one of the four nitrogenous bases that make up RNA.

Established cell lines Cell cultures capable of unlimited growth in vitro. Derived from continuous cell lines in which certain cells acquire selective advantages and an increased growth rate.

Complementary-determining regions, CDRs Hypervariable regions within the variable domains of antibody light and heavy chains that form the antigen-binding sites of the antibody molecule.

Transcription factor A protein that assists RNA polymerase through all Stages of Transcription and ensures the selectivity of the process.

Phenylketonuria A hereditary disorder characterized by impaired myelination of nerve fibers, a reduced number of melanocytes, seizures, and mental retardation, among other symptoms. It is caused by a disruption in phenylalanine metabolism due to phenylalanine hydroxylase deficiency and is inherited in an autosomal recessive manner.

Phenotype The totality of all traits of an organism, formed through the interaction of its genotype with the environment.

Phenotypic mixing, pseudotype formation The production of viral particles resulting from the packaging of the genetic material of one virus strain into the protein capsid of another during a mixed infection.

Fermentation In industrial microbiology, it is the large-scale cultivation of microorganisms in specialized vessels (fermenters, bioreactors).

Enzyme-linked immunosorbent assay (ELISA) A method for detecting specific molecules in a sample. The sample is immobilized on a solid support and incubated with an antibody specific to the target marker molecule (primary antibody). Unbound primary antibodies are washed away, and a secondary antibody that specifically binds to the primary antibody is added. The secondary antibody is conjugated to an enzyme that converts a colorless substrate into a colored product. A colorless substrate is then added, and the colored product is quantified.

Ferredoxin An iron-sulfur protein that acts as an electron carrier.

Fertility The ability of organisms to produce viable offspring.

Physical map The arrangement of genes on a chromosome determined using various methods (Electron Microscopy, sequencing, restriction mapping). Distances on such maps are measured in base pairs.

Nitrogen fixation The conversion of atmospheric nitrogen into ammonia, catalyzed by the enzyme Nitrogenase, which is found exclusively in prokaryotes.

Phytohormone A substance that stimulates plant growth or other physiological processes. Examples include Auxins, Cytokinins, and Ethylene.

Phytopathogen Organisms (such as fungi, bacteria, and viruses) that cause diseases in plants.

Flavonoids Phenolic Compounds synthesized by plants. Their structural backbone consists of two aromatic rings connected by a three-carbon bridge. They are responsible for plant pigmentation and provide protection against fungi and insects.

Fluorescein A fluorescent dye commonly used as an antibody label, enabling the visualization of antibodies after they bind to their target antigen.

Fluorophore A chemical group responsible for the fluorescence of a given compound.

Phosphodiester bond The linkage between the phosphate groups at the 3'- and 5'-carbon atoms of adjacent nucleotides in a single polynucleotide chain.

Photosynthesis The process by which higher plant cells convert visible light energy into chemical bond energy, accompanied by the formation of Organic compounds and oxygen from carbon dioxide and Water.

Klenow fragment The larger of the two fragments produced by the proteolytic cleavage of E. coli DNA polymerase I. It retains 5'→3' polymerase activity and 3'→5' exonuclease activity, and is widely used in DNA Sequencing, among other Applications.

DNA shearing The breakage of DNA molecules under the action of hydrodynamic forces (e.g., when passing a DNA solution through a syringe needle). These forces arise in a solution due to the sliding of one fluid layer relative to another.

Functional cloning The identification of a gene based on the known amino acid sequence of its protein product.

Footprinting A method for identifying DNA regions that specifically bind to proteins. It relies on the protection of DNA segments involved in protein-contact sites from endonuclease digestion.

Chemiluminescence The emission of light during a chemical reaction.

Chimera An organism composed of cells, tissues, and Organs derived from different individuals.

Chitinase An enzyme synthesized by plants upon infection by pathogenic fungi; it hydrolyzes the Chitin in fungal cell walls. Chitinase is also produced by certain bacteria.

Holoenzyme An enzyme molecule comprising all subunits and cofactors necessary for its catalytic function.

Chromogenic substrate A substance that develops a characteristic color upon cleavage by a specific enzyme.

Chromosome A structure based on a condensed DNA molecule that serves as the carrier of genetic information. It is capable of replication while maintaining its Structural and functional individuality across generations. In eukaryotes, chromosomes are located within the Cell Nucleus, whereas in prokaryotes they reside directly in the Cytoplasm.

Chromosomal integration site A specific locus on a chromosome where foreign DNA can integrate, often without any adverse consequences for the host organism.

X-linked gene A gene localized exclusively on the X chromosome.

Cellulose A high-molecular-weight linear polysaccharide composed of ß-D-glucose residues linked by (1,4)-bonds. It plays a key role in forming the structural Skeleton of plant cells.

Cellulosome A multi-enzyme protein complex found in certain cellulolytic microorganisms that contains all the enzymes necessary for the complete breakdown of cellulose.

Sucrose density gradient centrifugation A technique used to separate macromolecules based on their shape and size, relying on differences in their sedimentation coefficients.

Cyclic AMP, cAMP (Cyclic AMP) Cyclic adenosine monophosphate, a molecule involved in A wide variety of intracellular regulatory pathways.

Zinc fingers DNA-binding domains containing two cysteine residues and one Histidine residue. These amino acids coordinate with a zinc ion, while the stretch of the polypeptide chain between them loops out to form a finger-like structure.

Cistron A genetic unit equivalent to a gene, encoding a single polypeptide chain.

Cytosine, C (Cytosine) One of the four nitrogenous bases found in DNA and RNA.

Cytokinins A class of Plant Hormones that promote cell division.

Allelic frequency The proportion of a particular allele at a given locus relative to the sum of all alleles at that locus in a sufficiently large population of individuals.

Codon usage The average frequency with which different codons are used by a given organism, calculated from a large sample of structural genes.

Recombination frequency, recombination index The proportion of recombinant offspring (or recombinant chromosomes) relative to the total number of progeny (or chromosomes).

Transformation frequency The fraction of cells in a population that have successfully taken up foreign DNA, expressed as The ratio of transformants to the total number of cells.

Shuttle vector A plasmid DNA molecule capable of replicating in two different host systems (e.g., in E. coli and yeast cells).

Shine—Dalgarno sequence, ribosome-binding site A nucleotide sequence located upstream of the start codon on mRNA (typically AGGAGG) that pairs with the complementary sequence of the RNA component (rRNA) of the small ribosomal subunit.

Strain A culture of genetically uniform microorganisms.

Exogenous DNA DNA isolated from a donor organism and introduced into a vector or the chromosomal DNA of a host organism. Also referred to as foreign and heterologous DNA.

Exon A region of a gene present in the primary transcript that remains after RNA Processing (removal of introns). Together with other exons, it forms mature mRNA.

Exonuclease III An E. coli exonuclease that specifically removes nucleotides from the 3'-ends of double-stranded DNA.

Exopolysaccharide A high-molecular-weight polymer composed of sugar residues secreted into the extracellular environment by certain microorganisms.

Expressivity The degree of phenotypic expression of a hereditary trait encoded by a given allele. A distinction is made between constant expressivity (when the trait shows no variation) and variable expressivity.

Expression vector A plasmid vector engineered so that the cloned gene is expressed only during a specific phase of the Cell Cycle AND for a controlled duration. This is typically achieved by incorporating a strong regulated promoter into the plasmid.

Expression The transcription and translation of a gene.

Electroporation The formation of transient pores in cell membranes induced by an electric pulse, allowing foreign DNA to enter the cells.

Electrophoresis A technique for separating charged molecules (such as DNA, RNA, or proteins) based on their differential migration rates in an electric field.

Elongation The sequential addition of monomers to a growing polymer chain.

Embryonic Stem Cells, ES cells Cells derived from the blastocyst stage of an embryo, capable of differentiating into any cell type, including germline cells, when introduced into another blastocyst-stage embryo.

Endonuclease An enzyme that hydrolyzes internal phosphodiester bonds and cleaves DNA and RNA molecules. Endonucleases are involved in recombination, repair, and restriction; in the latter case, they are referred to as restriction enzymes (restriction endonucleases).

Endotoxin A toxin that is not secreted into the surrounding environment by the cell, but rather forms an integral part of the cell wall; many endotoxins are produced by Gram-negative bacteria and trigger inflammation.

Enterotoxin A bacterial protein that causes diarrhea upon entering the intestine.

Enhancer A specific DNA sequence that significantly increases the transcription rate of genes located on the same DNA molecule.

Epitope, antigenic determinant The part of an antigen molecule that interacts with the antigen-binding site of an antibody or a T-cell receptor.

Airlift fermenter (Airlift bioreactor) A cylindrical bioreactor in which mixing is achieved by a stream of gas introduced from the bottom.

Ethylene A gas that functions as a plant hormone. It promotes fruit ripening, flower preservation, seed germination, and ROOT formation, and is involved in plant stress responses.

Eukaryotes Organisms characterized by: 1) possessing a nucleus that contains chromosomes; 2) having various organelles in the cytoplasm, such as Mitochondria, Chloroplasts, etc. Eukaryotes include animals, plants, fungi, and certain algae.

Bystander effect The destruction of unmodified tumor cells by cytotoxic products synthesized by neighboring genetically modified cells.

Transformation efficiency The number of cells that have taken up foreign DNA relative to The amount of transforming DNA used. It is expressed as the number of transformants per 1 µg of DNA.

Effector A small molecule that binds to a repressor or an enzyme, leading to their inhibition or activation.

Effector cells Cells of the immune system that destroy antigens.

Nuclear cloning The generation of a living organism from an enucleated egg cell into which a diploid somatic nucleus has been implanted.