overdominance


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Related to overdominance: Multiple alleles

o·ver·dom·i·nance

(ō'vĕr-dom'i-năns),
That state in which the heterozygote has greater phenotype value and perhaps is more fit than the homozygous state for either of the alleles that it comprises. Compare: balanced polymorphism.

overdominance

(ō′vər-dŏm′ə-nəns)
n.
The condition of a heterozygote having a phenotype that is more pronounced or better adapted than that of either homozygote.

o′ver·dom′i·nant adj.

o·ver·dom·i·nance

(ō'vĕr-dom'i-năns)
That state in which the heterozygote has greater phenotype value and perhaps is more fit than the homozygous state for either of the alleles that it comprises.
Compare: balanced polymorphism

overdominance

a phenotypic condition in which the HETEROZYGOTE expresses a stronger manifestation of the trait than either HOMOZYGOTE. Overdominance produces heterozygous advantage that can maintain a GENETIC POLYMORPHISM in a population.
References in periodicals archive ?
Being greater or lesser than 1 show the relative dominance and overdominance of genes.
The high sea effects of the cross combinations involving low x low combiners could be due to overdominance and dominance x dominance type of gene action.
A prolonged debate has taken place during the past century between advocates of the overdominance or physiological stimulation theory versus the dominant favorable growth factors theory.
Mopper, unpublished data), but overdominance or frequency-dependent selection could produce the same result.
There are varying degrees of dominance, from partial to complete to overdominance.
deltoides parent contributed favorable alleles to increased height growth and displayed an overdominance effect over the P.
Of the 129 significant SNPs, 45 (11) SNPs had additive expression, 18 (2) dominance expression, and 29 (24) SNPs had both additive and dominant expression at 5% ChW (GW) level, of which 27 SNPs had overdominance effects, i.
Dominance, overdominance and epistasis condition the heterosis in two heterotic rice hybrids.
The genetic basis of heterosis has been attributed to several factors: overdominance at a single locus (East, 1936), pseudo-overdominance or dominance complementation, and multilocus epistatic interactions (Allard, 1996).
Assertiveness can spill into overdominance, overcontrolling and even bullying behaviour.
The size traits (wings and legs) showed a consistent pattern of overdominance as the hybrids had mean phenotypic values higher than both parents (see Appendix; [ILLUSTRATION FOR FIGURE 5 OMITTED]).