| ochre suppressor | A gene that codes for an altered tRNA so that its anticodon can recognise the ochre codon and thus allows the continuation of protein synthesis. A suppressor of an ochre mutation is a tRNA that is charged with the amino acid corresponding to the original codon or a neutral substitute. Ochre suppressors will also suppress amber codons. (18 Nov 1997) |
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| opal suppressor | <molecular biology> A gene that codes for an altered tRNA so that its anticodon can recognise the opal codon and thus allows the continuation of protein synthesis. A suppressor of an opal mutation is a tRNA that is charged with the amino acid corresponding to the original codon or a neutral substitute. Some eukaryote cells normally synthesise opal suppressor tRNAs. The function of these is not clear and they usually do not prevent normal termination of protein synthesis at an opal codon. (18 Nov 1997) |
| T-lymphocytes, suppressor-effector | Subpopulation of CD8+ T-lymphocytes which suppress antibody production or inhibit cellular immune responses. Suppressor-effector cells execute the message received from suppressor-inducer cells (T-lymphocytes, suppressor-inducer). (12 Dec 1998) |
| T-lymphocytes, suppressor-inducer | Subpopulation of CD4+ lymphocytes which induce CD8+ suppressor T-cells (T-lymphocytes, suppressor-effector) to suppress antibody production by B-cells. They also stimulate other cellular immune responses. (12 Dec 1998) |
| T suppressor cell | <haematology, immunology> Set of T lymphocytes (usually CD8) specifically involved in suppressing B-cell differentiation into antibody secreting cells. There may also be T suppresors of T-cell functions. (18 Nov 1997) |
| t-suppressor cell | A type of immune cells, also called t8 cells, these cells close down the immune response after it has destroyed invading organisms. T8 cells are sensitive to high concentrations of circulating lymphokine hormones and release their own lymphokines after an immune response has achieved its goal, signalling all other participants to cease their attack. Some memory B-cells remain to ward off a repeat attack by the invading organism. (12 Dec 1998) |
| tumour suppressor | <molecular biology, oncology> A gene that encodes a product that normally negatively regulates the cell cycle and that must be mutated or otherwise inactivated before a cell can proceed to rapid division. Examples: p53, RB retinoblastoma), WT 1 (Wilm's tumour), DCC (deleted in colonic carcinoma), NF 1 (neurofibrosarcoma) and APC adenomatous polyposis coli). (18 Nov 1997) |
| breast cancer susceptibility genes | Inherited factors that predispose to breast cancer. Put otherwise, these genes make one more susceptible to the disease and so increase the risk of developing breast cancer. Two of these genes, BRCA1 and BRCA2, have been identified (and prominently publicised). Several other genes (those for the Li-Fraumeni syndrome, Cowden disease, Muir-Torre syndrome, and ataxia-telangiectasia) are also known to predispose to breast cancer. However, since all of these known breast cancer susceptibility genes together do not account for more than a minor fraction (1/5th at most) of breast cancer that clusters in families, it is clear that more breast cancer genes remain to be discovered. (12 Dec 1998) |
| cancer, breast, susceptibility genes | Inherited factors that predispose to breast cancer. Put otherwise, these genes make one more susceptible to the disease and so increase the risk of developing breast cancer. Two of these genes, BRCA1 and BRCA2, have been identified (and prominently publicised). Several other genes (those for the Li-Fraumeni syndrome, Cowden disease, Muir-Torre syndrome, and ataxia-telangiectasia) are also known to predispose to breast cancer. However, since all of these known breast cancer susceptibility genes together do not account for more than a minor fraction (1/5th at most) of breast cancer that clusters in families, it is clear that more breast cancer genes remain to be discovered. (12 Dec 1998) |
| genes | Located in the nucleus of the cell, genes contain hereditary information that is transferred from cell to cell. (09 Oct 1997) |
| genes, abl | Retrovirus-associated DNA sequences (abl) originally isolated from the abelson murine leukaemia virus (ab-mulv). The proto-oncogene abl (c-abl) codes for a protein that is a member of the tyrosine kinase family. The human c-abl gene is located at 9q34.1 on the long arm of chromosome 9. It is activated by translocation to bcr on chromosome 22 in chronic myelogenous leukaemia. (12 Dec 1998) |
| genes, apc | Tumour suppressor genes located in the 5q21 region on the long arm of chromosome 5. The mutation of these genes is associated with familial adenomatous polyposis (apc stands for adenomatous polyposis coli) and gardner's syndrome, as well as some sporadic colourectal cancers. (12 Dec 1998) |
| genes, arac | Regulatory genes which encode a cyclic AMP receptor protein required for l-arabinose utilization in e. Coli. It is an example of positive control or regulation of gene expression in the bacterial operon. (12 Dec 1998) |
| genes, archaeal | The genetic material of archaea. (12 Dec 1998) |
| genes, bacterial | The genetic material of bacteria. (12 Dec 1998) |