%0 Journal Article %A Takafumi Katsumura %A Shoji Oda %A Shigeki Nakagome %A Tsunehiko Hanihara %A Hiroshi Kataoka %A Hiroshi Mitani %A Shoji Kawamura %A Hiroki Oota %T Natural Allelic Variations of Xenobiotic Enzymes Pleiotropically Affect Sexual Dimorphism in Oryzias latipes %D 2013 %R 10.1101/000661 %J bioRxiv %P 000661 %X Sexual dimorphisms, which are phenotypic differences between males and females, are driven by sexual selection [1, 2]. Interestingly, sexually selected traits show geographic variations within species despite strong directional selective pressures [3, 4]. However, genetic factors that regulate varied sexual differences remain unknown. In this study, we show that polymorphisms in cytochrome P450 (CYP) 1B1, which encodes a xenobiotic-metabolising enzyme, are associated with local differences of sexual dimorphisms in the anal fin morphology of medaka fish (Oryzias latipes). High and low activity CYP1B1 alleles increased and decreased differences in anal fin sizes, respectively. Behavioural and phylogenetic analyses suggest maintenance of the high activity allele by sexual selection, whereas the low activity allele may have evolved by positive selection due to by-product effects of CYP1B1. The present data can elucidate evolutionary mechanisms behind genetic variations in sexual dimorphism and indicate pleiotropic effects of xenobiotic enzymes. %U