| hemizygous gene | <genetics> Any gene which is present as only one copy in a diploid genome, when most other genes in the genome are present as two copies. The genes on the sex chromosomes of members of the heterogametic sex of a species are all hemizygous genes (for example: in humans, males have hemizygous genes on their X and Y chromosomes because they do not have two copies of either of those chromosomes). (13 Nov 1997) |
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| SCG10 gene | A neural specific gene that encodes a growth associated protein expressed early in the development of neuronal derivatives of the neural crest. The 22 kD intracellular protein is associated with the membranous organelles that accumulate in growth cones. (18 Nov 1997) |
| H gene | In laboratory animals, a gene which can elicit an immune response and thereby cause rejection of a homograft when tissue is transplanted from one individual to another; in humans, histocompatibility gene's control HLA antigens. Synonym: H gene. (05 Mar 2000) |
| X-linked gene | A gene located on an X chromosome. (05 Mar 2000) |
| histocompatibility gene | In laboratory animals, a gene which can elicit an immune response and thereby cause rejection of a homograft when tissue is transplanted from one individual to another; in humans, histocompatibility gene's control HLA antigens. Synonym: H gene. (05 Mar 2000) |
| histone gene | A histone gene is any gene which codes for histone proteins. (Histones help compact DNA so that it will fit into an eukaryotic cells nucleus). (09 Oct 1997) |
| holandric gene | A gene located on a Y chromosome. Synonym: holandric gene. (05 Mar 2000) |
| segmentation gene | <molecular biology> Genes required for the establishment of segmentation in the embryo. In Drosophila about 20 such genes are required. A development pattern of the embryo of the fruit fly Drosophila where the embryo looks like a stack of discs. Each disc is a segment, and each segment consists of two compartments (an anterior and posterior). Various parts of the adult fruit fly (wings, legs, eyes, etc.) arise from specific segments. (09 Oct 1997) |
| segment polarity gene | <molecular biology> A segmentation gene, responsible for specifying anterior posterior polarity within individual embryonic segments. In Drosophila, there are at least 10 such genes, for example gooseberry. (18 Nov 1997) |
| homeotic gene | <molecular biology> Gene, containing homeobox, the level of expression of which is set during embryongenesis in response to positional cues and which then directs the later formation of tissues and appendages appropriate to that part of the organism. Mutation of these genes leads to inappropriate expression of characteristics normally associated with another part of the organism (homeotic mutants. (18 Nov 1997) |
| homeotic selector gene | <molecular biology> The genes in the fruit fly Drosophila which code for the segmentation of the thorax (the bithorax complex) and the limbs and appendages, such as antennae and legs (antennapedia complex). (09 Oct 1997) |
| selector gene | <molecular biology> A group of genes that determines which part of a developmental pattern cells will be allocated within a developmental segment. (18 Nov 1997) |
| housekeeping gene | <molecular biology> The genes which are expressed in all cells and which code for molecules that are necessary for basic maintenance and essential cellular functions. (09 Oct 1997) |
| hox gene | <molecular biology> Homeobox containing genes of vertebrates. (18 Nov 1997) |
| human gene therapy | <molecular biology, technique> Insertion of normal DNA directly into cells to correct a genetic defect. (09 Oct 1997) |