Z linkage of female promiscuity genes in the moth Utetheisa ornatrix: support for the sexy-sperm hypothesis?
Female preference genes for large males in the highly promiscuous moth Utetheisa ornatrix (Lepidoptera: Arctiidae) have previously been shown to be mostly Z-linked, in accordance with the hypothesis that ZZ-ZW sex chromosome systems should facilitate Fisherian sexual selection. We determined the heritability of both female and male promiscuity in the highly promiscuous moth U. ornatrix (Lepidoptera: Arctiidae) through parent-offspring and grandparent-offspring regression analyses. Our data show that male promiscuity is not sex-limited and either autosomal or sex-linked whereas female promiscuity is primarily determined by sex-limited, Z-linked genes. These data are consistent with the "sexy-sperm hypothesis," which posits that multiple-mating and sperm competitiveness coevolve through a Fisherian-like process in which female promiscuity is a kind of mate choice in which sperm-competitiveness is the trait favored in males. Such a Fisherian process should also be more potent when female preferences are Z-linked and sex-limited than when autosomal or not limited.
Iyengar
Vikram K
VK
Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, Pennsylvania 19085, USA. vikram.iyengar@villanova.edu
Reeve
Hudson K
HK
D000818:Animals; D005260:Female; D008297:Male; D009036:Moths / Q000235:genetics* / Q000502:physiology; D012726:Sexual Behavior, Animal; D013094:Spermatozoa / Q000502:physiology*