An autosomal locus controls sex reversal in interspecific XY hybrids of the medaka fishes

作者：Kato M; Takehana Y; Fukuda Y; Naruse K; Sakaizumi M; Hamaguchi S^*

来源：Heredity, 2011, 107(6): 523-529.

DOI：10.1038/hdy.2011.38

• Dmy
• hybrids
• medaka
• sex-determining gene
• sex reversal

Although the two medaka species Oryzias latipes and O. curvinotus share the sex-determining gene Dmy, XY sex reversal occurs in interspecific hybridization between O. latipes females of the Hd-rR inbred strain and O. curvinotus males. In this Hd-rR-curvinotus mating, all XX and XY hybrids developed as females. In this study, we used another O. latipes inbred strain (HNI) for the mating, and found that 23% of XY hybrids developed as males, although all XX and the remaining XY hybrids developed as females. Linkage analysis using 236 XY hybrid males obtained from (Hd-rR x HNI) F(1) females showed that a single major locus, Hybrid maleless (Hml), on autosomal linkage group 17, contributed to the strain difference in the XY sex reversal. Furthermore, we found that crossing females of a different O. latipes inbred strain, HO4C, did not cause XY sex reversal in the interspecific hybrids, and that the XY hybrids from (Hd-rR x HO4C) F(1) females showed a 1: 1 sex ratio. XY hybrid males had the HO4C allele at sequence-tagged site loci around the Hml locus whereas XY females had the Hd-rR allele, confirming the strong contribution of this locus to XY sex reversal. Reverse transcriptase PCR analysis showed a reduced expression of Dmy(curvinotus) in XY fry of the Hd-rR-curvinotus hybrids at hatching. These results suggest that the Hd-rR allele at the Hml locus interfere with the function of Dmy(curvinotus) on a hybrid background, thus resulting in XY sex reversal. Heredity (2011) 107, 523-529; doi:10.1038/hdy.2011.38; published online 18 May 2011

• 出版日期2011-12