< i > Dmrt1 < /i > is the only male pathway gene tested indispensable for sex determination and functional testis development in tilapia

by Shuangshuang Qi, Shengfei Dai, Xin Zhou, Xueyan Wei, Ping Chen, Yuanyuan He, Thomas D. Kocher, Deshou Wang, Minghui Li

Sex is determined by multiple factors derived from somatic and germ cells in vertebrates. We have identifiedamhy,dmrt1,gsdf as male andfoxl2,foxl3,cyp19a1a as female sex determination pathway genes in Nile tilapia. However, the relationship among these genes is largely unclear. Here, we found that the gonads ofdmrt1;cyp19a1a double mutants developed as ovaries or underdeveloped testes with no germ cells irrespective of their genetic sex. In addition, the gonads ofdmrt1;cyp19a1a;cyp19a1b triple mutants still developed as ovaries. The gonads offoxl3;cyp19a1a double mutants developed as testes, while the gonads ofdmrt1;cyp19a1a;foxl3 triple mutants eventually developed as ovaries. In contrast, the gonads ofamhy;cyp19a1a,gsdf;cyp19a1a,amhy;foxl2,gsdf;foxl2 double andamhy;cyp19a1a;cyp19a1b,gsdf;cyp19a1a;cyp19a1b triple mutants developed as testes with spermatogenesis via up-regulation ofdmrt1 in both somatic and germ cells. The gonads ofamhy;foxl3 andgsdf;foxl3 double mutants developed as ovaries but with germ cells in spermatogenesis due to up-regulation ofdmrt1. Taking the respective ovary and underdeveloped testis ofdmrt1;foxl3 anddmrt1;foxl2 double mutants reported previously into consideration, we demonstrated that oncedmrt1 mutated, the gonad could not be rescued to functional testis by mutating any female pathway gene. The sex reversal caused by mutatio...

Source: PLoS Genetics - March 27, 2024 Category: Genetics & Stem Cells Authors: Shuangshuang Qi Source Type: research