Title The mechanisms of gonadal sex determination and differentiation in fish
Authers Tohru KOBAYASHI
Keywords sex determination, sex differentiation, DMY, DMRT1, estrogen
Citation Bull. Fish. Res. Agen. No.26, 107-114, 2008
Various genetic and molecular approaches have been used to investigate the mechanisms of sex determination, gonadal sex differentiation, and sex change in fish. Although the sex of most animals is determined by genetic information, sex-determining genes had been identified only in mammals, several flies, and the worm Caenorhabditis elegans until the recent discovery of DMY (DM- domain gene on the Y chromosome) in the sex-determining region on the Y chromosome of the teleost fish medaka, Oryzias latipes. We identified, for the first time in non-mammalian vertebrates, DMY, as the sex-determining gene of medaka. In tilapia,, Oreochromis niloticus, Foxl2/endogenous estrogens act as the natural inducers of ovarian differentiation, while DMRT1 may be important for testicular differentiation. In the protogynous wrasse, a rapid decline in serum estradiol-17beta levels may be an initial trigger of the female-to-male sex change.
URI http://www.fra.affrc.go.jp/bulletin/bull/bull26/kobayashi.pdf