at Related Biological Terms

The synthesis of multiple copies of a specific gene, which remain as tandem repeats within the chromosome or are segregated as satellite DNA.

A method for the production of up to 1010 protein molecules per DNA by a continuous process in a homogeneous solution. Resto, E., Iida, A., Van Cleve, M.D. and Hecht, S.M. (1992) Nucleic Acids Res. 20, 5979-5983

The inherited appearance of multiple copies of a gene. Duplication may result in identical or defective copies, either as tandem repeats at the original chromosomal locus, at a neighboring locus or at a completely different locus. Duplication may be benign or may be the basis of a pathology. If benign, one of the copies will be freed of any selective pressure and may evolve a new function.see gene amplification

Recombination between homologous chromosomes that may occur during meiosis anywhere along their lengths. (see also Holliday model; Meselson-Radding model)

A DNA sequencing method that involves PCR amplification of the target and uses a primer with an attached phage promoter sequence, transcription to produce a single-stranded RNA and reverse transcription with dideoxy terminator nucleotides that upon electrophoresis will generate a sequencing ladder. Buerstedde, J.-M. and Sommer, S.S. (1991) in PCR Topics: Usage of Polymerase Chain Reaction in Genetic and Infectious Diseases (Rolfs, A., Schumacher, H.C. and Marx, P., eds.), pp. 9-14, Springer-Verlag, Berlin

A method to detect and isolate DNA sequences that are candidate genes for inherited disorders for which the gene product is unknown, based on the absence of mismatches in DNA sequences between an affected individual and a heterozygous or carrier progenitor. Large DNA segments are prepared from the genomic DNA of the two related individuals in such a way (e.g. by leaving 3'-overhangs) that they will not be degraded by subsequent exonuclease digestion, e.g. by ExoIII. The DNA from one individual is enzymically methylated and annealed with the DNA of the second, heterohybrids (two methylated or two unmethylated strands) are cleaved by appropriate endonucleases, e.g. DpnI and MboI, and the uncleaved duplexes are scanned for single-base mismatches by methyl-directed mismatch repair enzymes that leave single-strand nicks that are attacked by ExoIII. The duplexes that survive all these tests are those that are shared by the two related individuals and are therefore candidates for the affected gene. Nelson, S.F., McCusker, J.H., Sander, M.A., et al. (1993) Nature genet. 4, 11-17; Kolodner, R.D. (1995) Trends Biochem. Sci. 20, 387-401

A metabolite that regulates many operons, e.g. glucose, as it regulates several anabolic reactions in a bacterium.

A series of operons that are induced together, e.g. the genes for the heat-shock proteins or those for the SOS repair proteins.

The reversible condensation of the carbonyl group of a sugar with an amino group of a protein to form a Schiff base that often triggers subsequent irreversible rearrangements, e.g. the condensation of glucose with haemoglobin A to form haemoglobin A1c.

A compound composed of an oligosaccharide linked to a protein or lipid, e.g. mucins (which are glycoproteins), globosides (which are N-acetylsphingosine conjugates of oligosaccharides), and the endotoxin of Gram-negative bacteria. (see also lipopolysaccharide (LPS))