Codominance


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Related to Codominance: Multiple alleles, incomplete dominance

codominance

[kō′däm·ə·nəns]
(genetics)
A condition in which each allele of a heterozygous pair expresses itself fully, as in human blood group AB individuals.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Codominance

 

expression in heterozygotes of characters typical of both forms (alleles) of the gene.

Codominance is found, for example, in studying blood serum proteins (transferrins). In individuals heterozygous for the alleles controlling the biosynthesis of transferrin, both forms of this protein are present in the blood at the same time, and each form is found separately in the corresponding homozygote. The same patterns of heredity are also found in other proteins, including almost all the enzymes. The degree of activity of each of the allelic genes may be different. The products synthesized under the control of two alleles of the same gene may independently influence the expression of a character or they may interact with each other. The existence of codominance is useful in studying the genetic structure of populations without making crossings or studying pedigrees; instead, modern biochemical and immunological methods of separating proteins are used. Codominance in erythrocytic antigens facilitates the identification of blood groups in man and animals.

V. S. KIRPICHNIKOV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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Blood type is an example of codominance, and coat color is an example of partial dominance.
In the latter, changes in community composition over the last 12,000 years are consistently characterized by the alternation and codominance of Quercus and Pinus (Costa et al., 1990; Reille & Pons, 1992; YlI et al., 1995).
In SSI, codominance or dominance relations between SI alleles in the ovule-parent determine the style phenotype, whereas similar or different codominance or dominance relations in the pollen-parent determine the pollen phenotype (Ockendon 1974; Kowyama et al.
If not detoxified, they bind to macromolecules producing a hypersensitivity reaction by either cell death or neoantigen formation; therefore, patients with hypersensitivity appear to have a defect in epoxide hydrolase.[7] Cross-sensitivity between phenytoin, phenobarbital, and carbemazepine appears to occur in 80% of patients, suggesting that patients who have had a reaction to phenytoin, phenobarbital, or carbemazepine should not be treated with these or any other arene-oxide-producing drugs.[5] In vitro, both parents of hypersensitive individuals have demonstrated intermediate cell death, which suggests an autosomal codominance inheritance pattern.
The local codominance of such a guild of legumes on this edaphically extreme site suggests that there is a selective advantage in the trees being ectomycorrhizal as opposed to being arbuscular (or non-) mycorrhizal.
This pattern of codominance may reflect different advantages of each species under different environmental conditions.
The availability and abundance of SSR markers throughout the cotton genome, their polymorphic nature, codominance, and polymerase chain reaction (PCR)-based assay make SSRs useful in detecting genetic diversity (Reddy et al., 2001).
Because the initial experiment was designed for the analysis of a fertilizer treatment response, trees were selected for codominance in the canopy and understory trees were avoided.
They also exhibit other desired qualities, that is, neutrality, Mendelian inheritance, and codominance. However, microsatellites probably evolve under peculiar models of mutation, and exhibit high mutation rates (Charlesworth et al.
- The mean basal areas for each species from the baseline runs [ILLUSTRATION FOR FIGURE 7A OMITTED] show a familiar successional pattern, with shade intolerant species initially dominant, but declining after reaching peak abundances between years 100 (WA) and 400 (YB), and subsequent late successional codominance by Be and Hm.
For example, Themeda triandra, a highly palatable East African savanna grass, suffers [approximately equal to]80% mortality from ungulate grazers when not associated with other, less palatable grass species; however, as codominance with unpalatable species increases, mortality of Themeda rapidly decreases (McNaughton, 1978).
1996), which benefit from their high polymorphism, heterozygosity, codominance, and wide transportability across different mapping populations.