Haldane's rule in taxa lacking a hemizygous X.
Haldane's rule states that species hybrids of the XY sex are preferentially sterile or inviable. In all taxa known to obey this rule, the Y is inert and X-linked genes show full expression in XY individuals. Until recently, all theories of Haldane's rule depended on this hemizygosity. A test of Haldane's rule in animals lacking a hemizygous sex-mosquitoes having two functional sex chromosomes in both sexes-reveals that these species show Haldane's rule for sterility but not inviability. A related group having a "normal" hemizygous X obeys Haldane's rule for both sterility and inviability. These results support the faster male and dominance theories of Haldane's rule.
Presgraves
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DC
Department of Biology, University of Rochester, Rochester, NY 14627, USA.
Orr
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HA
D000330:Aedes / Q000235:genetics* / Q000502:physiology; D000818:Animals; D000852:Anopheles / Q000235:genetics* / Q000502:physiology; D005075:Biological Evolution; D003433:Crosses, Genetic; D005260:Female; D005298:Fertility / Q000235:genetics; D005799:Genes, Dominant; D005808:Genes, Recessive; D005828:Genetics, Population; D005838:Genotype; D006824:Hybridization, Genetic; D007246:Infertility; D008297:Male; D008957:Models, Genetic; D012727:Sex Characteristics; D014960:X Chromosome / Q000502:physiology*