Artificially induced sex-reversal leads to transition from genetic to temperature-dependent sex determination in fish species

Dear Editor,Sex determination is highly plastic across vertebrates.The mechanisms of sex determination can be broadly divided into genetic sex determination(GSD)and environmental sex determination(ESD).GSD is the most popular sex-determining type in vertebrates,while ESD mainly occurred in some fish and reptiles(Li and Gui,2018a,2018b).Sex determination in teleost fish is usually controlled by the interaction between genetic and environmental factors(Mei and Gui,2015).Naturally,the coexistence of GSD and ESD(temperature・dependent sex determination)was found in several fish species including gibel carp(Carassius gibelio)and half-smooth tongue sole(Cynoglossus semilaevis)(Li and Gui,2018b),as well as in bearded dragon(Pogona vitticeps)(Holleley et al.,2015).However,the exact mechanism of transition between GSD and ESD is unclear.