heterogametic sex


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Related to heterogametic sex: homogametic

heterogametic sex

the sex of a particular organism that contains within each nucleus one X-chromosome and one Y-chromosome (or just one X-chromosome), and therefore produces two different types of gamete with respect to the SEX CHROMOSOMES. Usually the male is the heterogametic sex but in some organisms (e.g. birds), it is the female. Since the sex chromosomes usually are responsible for SEX DETERMINATION, it is the heterogametic parent that controls the sex of the offspring.

heterogametic sex

the sex which produces gametes containing dissimilar sex chromosomes, i.e. males in all mammalian species.
References in periodicals archive ?
The cause of this difference was not clear, although de Kogel (1997) points out that it is consistent with unguarded-sex-chromosome explanations for higher mortality in the heterogametic sex.
These authors suggest that the frequent co-occurrence of sex-ratio distorters and suppressors could explain Haldane's rule - the fact that when one sex is affected in hybrid crosses, it is generally the heterogametic sex (Haldane 1922).
This reduced fitness of the heterogametic sex appears to be a behavioral manifestation of Haldane's Rule (Haldane 1922): if one hybrid sex is sterile or inviable, it tends to be the heterogametic sex.
1] hybrids is sexually asymmetrical, it is usually higher in the heterogametic sex (Haldane 1922).
Because in the Lepidoptera the females are the heterogametic sex, the expectation from Haldane's Rule is that the female hybrids should be sterile, rare or absent.
Much research on the genetics of speciation is devoted to elucidating the underlying genetics of Haldane's rule (Haldane 1922): the observation that in interspecific crosses the sterile or inviable sex is nearly always the heterogametic sex (see Coyne and Orr 1989; Wu et al.
Haldane (1922) observed that when hybridization occurs between different animal races, the heterogametic sex more often suffers reduced survivorship or fertility than the homogametic sex.