| genes, nitrogen fixation | Regulatory and structural genes present in certain bacteria, algae and fungi that control the conversion of atmospheric nitrogen into biologically usable compounds; include nif structural genes (e.g., nifd, nifh) for nitrogenase and nitrate reductase as well as regulator genes nifa, nifb, ntra, ntrb, ntrc. Some are responsible for regulating transcription of genes involved in the assimilation of poor nitrogen sources in enteric bacteria. (12 Dec 1998) |
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| genes, overlapping | Genes whose nucleotide sequences overlap to some degree. The overlapped sequences may involve structural or regulatory genes of eukaryotic or prokaryotic cells. (12 Dec 1998) |
| genes, p16 | Tumour suppressor genes located on human chromosome 9 in the region 9p21. This gene is either deleted or mutated in a wide range of malignancies. (12 Dec 1998) |
| genes, p53 | Tumour suppressor genes located on the short arm of human chromosome 17 and coding for the phosphoprotein p53. (12 Dec 1998) |
| genes, plant | The hereditary material of plants. (12 Dec 1998) |
| genes, pol | DNA sequences that form the coding region for retroviral enzymes including reverse transcriptase, protease, and endonuclease/integrase. "pol" is short for polymerase, the enzyme class of reverse transcriptase. (12 Dec 1998) |
| genes, protozoan | The genetic material of protozoa. (12 Dec 1998) |
| genes, px | DNA sequences that form the coding region for at least three proteins which regulate the expression of HTLV-I and HTLV-II. The proteins are p21(x), p27(rex), and p40(tax). The tax (trans-activator x) and rex (regulator x) genes are part of px but are in overlapping reading frames. X was the original designation for the sequences or region (at that time of unknown function) in the long open reading frame (lor) which is now called px. (12 Dec 1998) |
| genes, rag-1 | Genes involved in activating the enzyme vdj recombinase. Rag-1 is located on chromosome 11 in humans (chromosome 2 in mice) and is expressed exclusively in maturing lymphocytes. (12 Dec 1998) |
| genes, ras | Family of retrovirus-associated DNA sequences (ras) originally isolated from harvey (h-ras, ha-ras, rash) and kirsten (k-ras, ki-ras, rask) murine sarcoma viruses. Ras genes are widely conserved among animal species and sequences corresponding to both h-ras and k-ras genes have been detected in human, avian, murine, and non-vertebrate genomes. The closely related n-ras gene has been detected in human neuroblastoma and sarcoma cell lines. All genes of the family have a similar exon-intron structure and each encodes a p21 protein. (12 Dec 1998) |
| genes, recessive | Genes that are reflected in the phenotype only in the homozygous state. (12 Dec 1998) |
| genes, regulator | Genes which regulate or circumscribe the activity of other genes; specifically, genes which code for proteins (repressors or activators) which regulate the genetic transcription of the structural genes and/or regulatory genes. (12 Dec 1998) |
| genes, reporter | Genes whose expression is easily detectable and therefore used to study promoter activity at many positions in a target genome. In recombinant DNA technology, these genes may be attached to a promoter region of interest. (12 Dec 1998) |
| genes, retinoblastoma | Tumour suppressor genes located on human chromosome 13 in the region 13q14 and coding for a family of phosphoproteins with molecular weights ranging from 104 kD to 115 kD. One copy of the wild-type rb gene is necessary for normal retinal development. Loss or inactivation of both alleles at this locus results in retinoblastoma. (12 Dec 1998) |
| genes, rev | DNA sequences that form the coding region for a protein that regulates the expression of the viral structural and regulatory proteins in human immunodeficiency virus (HIV). Rev is short for regulator of virion. (12 Dec 1998) |