Reduced recombination between X and Y chromosomes may be selected even in the absence of multiple sex determining loci in the case of sexually antagonistic genes in which alleles that are favored in one sex are disfavored in the other. A notable example of this is seen in the ZFX geneFig.
J Roy Stat Soc B 39 : 1— The longevity gender gap: are telomeres the explanation? Detection and analysis of a glucose 6-phosphate dehydrogenase phenotype B cell line contamination. Compared with the previously reported RH map Mellersh et al. Shulman LM, Bhat V.
Categories : Sexual dimorphism Evolutionary biology Selection. This phenotypic variation can play a key role in the evolution of various species and their sexual differentiation. This leaves males with the responsibility of providing food regularly and securing and maintaining a high-quality territory for nesting.
The X chromosome makes a very small percentage of the total human genome and the epigenetics of this chromosome is a major contributor to certain diseases. Multiple matings is a classic example of competing optimal strategies.
Updated February 07, The sperm cell determines the sex of an individual. This is atypical because sex-limited traits are almost always heritable within the sex in which they are expressed. However, a female egg cell may carry only an X sex chromosome.
For this species, the timing of egg-laying has much to do with male behavior.
Groot C, Margolis L Although the accuracy and utility of the map are evidenced by the localization of disease loci for canine renal cancer, narcolepsy, multiple forms of retinitis pigmentosa, hematologic disorders, and several metabolic diseases e.
Dopaminergic neurons from female rat fetuses, in dissociated cell cultures, are morphologically distinct from those obtained from male rat fetuses, differences that are present even when gonadal hormones are absent New York: Academic, , p. Chromosome assignments were made according to the nomenclature of the International Committee for the Standardization of the Dog Karyotype Switonski et al.