overdominance


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Related to overdominance: Multiple alleles

overdominance

[¦ō·vər′däm·ə·nəns]
(genetics)
Monohybrid heterosis, that is, the phenotype is being more pronounced in the heterozygote than in either homozygote with respect to a specified pair of alleles.
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In Boer, Matou and Nubi goats, the 651A/G in exon 2 was suggested as a useful marker for litter size of the second parity, showing an overdominance effect (Wu et al., 2009).
[19] found that epistasis and overdominance were important for heterosis.
The ratio [([H.sub.1]/D).sup.1/2] suggested overdominance gene action in both environments.
On the other hand, there was an overdominance effect of the resistance phenotype, with F1 hybrids showing greater resistance than the parental [H.sub.III] line (Figures 6(a), 6(b),and 6(c)).
In 1986, Koroleva studied in a diallel project the seed weight per plant, weight of 1000 barley seeds in [F.sub.1] and [F.sub.2], and in both studied traits gene overdominance was observed.
Rugby union has become a dour game, with too much emphasis on physical strength and scant reward for the admirable skills of footwork and handling, compounded by the overdominance of the kicker in deciding the result of a large number of games.
(262) The overdominance of the Security Service in this process is evident in these rules of nondisclosure.
Heterosis and overdominance following long-term selection for body weight in Japanese quail.
Do extra exercises in order to decrease the overdominance of the quads.
Unlike positive or negative selection, which usually reduce genetic variability, increasing or decreasing the frequency of a particular genetic variant, many types of selection maintain polymorphisms, especially when overdominance, spatially heterogeneous environments, temporally varying environments, or epistasis are occurring.
"Another theory for heterosis, supported by our discovery, postulates that improved vigor stems from only a single gene - an effect called "superdominance" or "overdominance"," he added.