Effects of sex steroid hormones (estradiol and testosterone) on growth traits of female, male and pseduo-male Chinese tongue sole (Cynoglossus semilaevis)

A variety of fish, including Chinese tongue sole (Cynoglossus semilaevis), have sexual size dimorphism, and this growth dimorphism may be related to the interaction of sex steroid hormones and growth axis-related genes. For the early stage of this study, transcriptomics analysis has found that sex steroid hormones might be involved in the growth regulation of Chinese tongue sole. In order to explore the effect of sex steroid hormones on the growth difference of different sexes of Chinese tongue sole, we injected 16-month-old female, male and pseudo-male fish with estradiol and testosterone hormones, and measured the growth hormone 1 (gh1), insulin-like growth factor 1 (igf1) and suppressor of cytokine signaling 3 (socs3) for quantitative analysis. The results reveal that the two sex steroid hormones had inhibitory effects on the growth performance of individuals of different sexes of Chinese tongue sole. After the treatment, the expressions of gh1 and igf1 in the brain and liver showed an overall downward trend, and the expression of socs3 in the muscle and liver increased significantly, indicating that the growth performance of fish had declined. By exploring the effects of sex steroid hormones on the growth performance of different sexes of Chinese tongue sole, we provide references for the in-depth study of sex steroid hormones in the regulation of fish sex size abnormalities.