Estrone exposure-induced feminization in male Siniperca chuatsi: A multidimensional study on sex reversal, liver...

Estrone (E1) is one of the primary natural estrogens found in aquatic environments and has the potential to impact the reproductive and endocrine systems of fish. To evaluate the impact of E1 on Siniperca chuatsi, in this study, male S. chuatsi were exposed to E1 at concentrations of 0.0, 0.01, 0.1, and 1.0 μg/L for 60 consecutive days. Subsequently, we analyzed the gonadal histology, hepatic histology, antioxidant enzyme activities, and transcriptomic analysis of the fish. Histological examination of the gonads revealed that high concentrations of E1 can induce the transformation of testes into ovaries in male S.chuatsi, with an induction rate of 80 %. Moreover, significant changes in the levels of the androgen 11-ketotestosterone and the estrogen were observed at high concentrations. Hepatic histology revealed that E1 exposure led to vacuolization of hepatocytes, pyknosis, and inflammation in the liver. Additionally, exposure to 1.0 μg/L E1 significantly increased the activities of SOD (superoxide dismutase) and T-AOC (total antioxidant capacity) in the liver. Transcriptomic analysis of the liver identified several genes significantly associated with sex differentiation, including vtg1, cyp19a, hsd17β3, and esr1, among others. GO and KEGG enrichment analyses suggested that E1 exposure significantly altered the level of lipid metabolism in the liver of male S. chuatsi. In summary, these results indicate that E1 exposure not only causes oxidative damage to the liver but also induces alterations in hepatic steroid hormone synthesis and lipid metabolism pathways, which are indicative of feminizing endocrine effects, thereby leading to the feminization of male S.chuatsi.