a property which is shown by some alleles. When the alleles are present in a heterozygous state they produce a different phenotype from that produced by either allele in the homozygous state.
A phenomenon in which two alleles of the same gene are fully expressed in the phenotype when both are present in a heterozygote. Blood type is an example of codominance.
Equal effect on the phenotype of two alleles of the same locus (as opposed to recessive and dominant).
cases where two or more dominant alleles exist for a single gene. Both dominant alleles are expressed in heterozygotes. An example is the ABO blood type in humans.
( genic selection) The equal contribution to fitness made by the two alleles at a locus in a diploid organism.
The equal expression of both copies of a gene in an individual eg. presence of both haemoglobin A and S on electrophoresis in an individual heterozygous for sickle-cell disease.
The relationship between a pair of alleles which both contribute to the phenotype of a heterozygote.
The observation of a phenotype caused by independent expression of both alleles of a gene in a diploid.
The situation in which a heterozygote shows the phenotypic effects of both alleles equally.
A type of inheritance in which heterozygotes fully express both alleles.
Situation in which two different alleles for a genetic trait are both expressed. See also: autosomal dominant, recessive gene
( Ecol.). The sharing of dominance by two or more species.
Defined for pairs of alleles. The situation in which an animal heterozygous for two alleles (A1 and A2 at the A locus) expresses both of the phenotypes observed in the two corresponding homozygotes. Thus, the heterozygote (A1/A2) and both homozygotes (A1/A1 and A2/A2) are all distinguishable from each other and A1 and A2 would be considered to be "codominant". This term has also been co-opted to describe DNA markers defined by alternative visible allelic forms such as different sized restriction fragments or PCR products.
A mode of inheritance in which the heterozygote has a phenotype that is different the phenotypes of either homozygotes. For instance for human blood type, if one homozygote is Type A, the other Type B, then the heterozygote will be Type AB. Codominance arises if both genes in the gene pair express a product.
When both alleles are expressed in the heterozygote.
The situation in which two different alleles for a trait are expressed unblended in the phenotype of heterozygous individuals. Neither allele is dominant or recessive, so that both influence the phenotype. Type AB Blood is an example. Such traits are said to be codominant.
Condition in which individual, unblended characteristics of two alleles are reflected in the phenotype.