| neurogenic gene | Best described in Drosophila, genes that are required to determine a neuronal fate. Examples: Notch, Delta. (18 Nov 1997) |
|---|---|
| structural gene | A gene that codes for a product (e.g. An enzyme, structural protein, tRNA), as opposed to a gene that serves a regulatory role. (18 Nov 1997) |
| nif gene | <molecular biology> The complex of genes in nitrogen fixing bacteria that code for the proteins required for nitrogen fixation, particularly the nitrogenase. Present as an operon in Klebsiella and carried on plasmid in Rhizobium which inhabit the roots of leguminous plants. (13 Nov 1997) |
| d4dr gene | <molecular biology> A gene which regulates a protein that plays a role in transmitting messages carried by dopamine between neurons (brain cells). A particular form of the gene may have an affect on an individual's personality since it seems to occur in individuals with novelty-seeking behaviour. (09 Oct 1997) |
| dam gene | <molecular biology> A gene that codes for the synthesis of a DNA adenine methylase. (09 Oct 1997) |
| supressor gene | <molecular biology> A gene that can reverse the effect of a mutation in other genes. (14 Nov 1997) |
| syntenic gene | <molecular biology> Genes that are believed to belocated on the same chromosome because they are lost along with a marker gene that is known to be located on that chromosome. (19 Jan 1998) |
| D gene segment | <molecular biology> Diversity gene segment. Part of the gene for the immunoglobin heavy chain, it codes for part of the hypervariable region of the VH domain and is located between the VH and JH segments. There are probably about 20 different D segments. (18 Nov 1997) |
| differential gene expression | Gene expression that responds to signals or triggers; a means of gene regulation; e.g., effects of certain hormones on protein biosynthesis. (05 Mar 2000) |
| diseases, single-gene | Hereditary disorders caused by a change (mutation) in a single gene. There are thousands of single-gene diseases including achondroplastic dwarfism, Huntington disease, cystic fibrosis, sickle cell disease, Duchenne muscular dystrophy, and haemophilia. Single-gene diseases typically describe classic simple Mendelian patterns of inheritance (as autosomal dominant, autosomal recessive, and X-linked traits) by comparison with polygenic diseases. (12 Dec 1998) |
| DNAa gene | <molecular biology> A defective gene of the bacteria Escherichia coli which produces a defective protein that influences DNA replication. (09 Oct 1997) |
| DNAb gene | <molecular biology> A gene found in the bacteria Escherichia coli which makes a protein that is involved in the formation of primer polynucleotide chains, which are precursors of DNA replication. (09 Oct 1997) |
| DNAe gene | <molecular biology> A gene found in the bacteria Escherichia coli which makes some of the components of the DNA Polymerase III protein, an enzyme which plays an important role in DNA replication. (09 Oct 1997) |
| DNAf gene | <molecular biology> A gene which codes for an enzyme (ribonucleotide reductase) which breaks down ribonucleotides. (09 Oct 1997) |
| DNAg gene | <molecular biology> A gene found in the bacteria Escherichia coli which makes the enzyme primase, an enzyme which helps make primers, which are precursors to DNA replication. (09 Oct 1997) |