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.

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

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A bay scallop sample (CR) obtained from a hatchery and used for mtDNA RFLP analysis by Blake and Graves (1995) also had codominant haplotypes, suggesting that the codominance of H2 and H3 we observed resulted from supplementation with hatchery bay scallops.
gene heredity mutation mitosis embryo allele helix clone sequence polymer autosome phenotype recessive metaphase locus polymerase telophase oligonucleotide geneticist interphase prophase phage bacteriophage chromomere transduction transformation nucleus Mendelian genome meiosis chromosome recombinant pedigree plasmid vector replicon nucleosome chromatography zygote centromere anaphase genotype endonuclease backcross exonuclease polyploidy diakinesis cytogenetics crossover segregate codominance dominance translocation nucleolus
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.
alata the most common, with varying codominance of D.