Uncovering the transcriptional landscape of estrogen-induced gonadal feminization in the Chinese giant salamander

This study investigates the transcriptomic landscape of estrogen treatment in the Chinese giant salamander (Andrias davidianus). Estrogen promotes and maintains the sex reversal process from male to female gonads at this stage by upregulating the expression of meiosis-related genes. Meanwhile, estrogen suppresses the expression of the DMRT1 gene, thereby inhibiting male gonadal differentiation pathways and inducing feminization of the male gonads. Furthermore, early estrogen induction upregulates the expression of CYP19A; however, as exogenous estrogen gradually accumulates, it replaces the hormone-induced synthesis function of CYP19A, leading to a gradual degeneration of CYP19A gene function in the gonads of the Chinese giant salamander. This research provides insights into the mechanisms of sex reversal induced by exogenous estrogen in both male and female gonads. It holds important implications for the development of all-male offspring to improve aquaculture productivity and for the conservation of wild Chinese giant salamander populations that may be exposed to estrogen contamination in natural water bodies.