Effect of Estradiol on Estrogen Nuclear Receptors Genes Expression on Embryonic Development Stages in Chinese Soft-Shelled Turtle (<i>Pelodiscus sinensis</i>)

Among Chinese soft-shelled turtles, <i>Pelodiscus sinensis</i>, males have a richer nutritional value and higher market price than females. All-male offspring were obtained by 17β-estradiol (E2). However, the molecular mechanisms of E2 inducing sexual reversal remain unclear. In this study, we cloned estrogen nuclear receptors (ERs) from <i>P. sinensis</i> and investigated their expression profiles. We examined the responses of ERα and ERβ after treatment with different concentrations of 1.0, 5.0, and 10 mg/mL E2. ERs showed abundant expressions in the adult gonad, <i>ERα</i> for ovary, and <i>ERβ</i> for testis. E2 can up-regulate the expression of <i>ERα</i>, which showed a remarkable increase while the promotion of <i>ERβ</i> was unobvious. They reached a high level at stage 17 after the treatment of E2, genes of the female-related genes <i>Rspo1</i>, <i>Wnt4</i>, β-catenin, <i>Foxl2</i>, <i>Cyp19a1,</i> and <i>Sox3</i> exhibited a significant raise at stage 17 with the increase in the concentration of E2 while the male-related genes <i>Sox9</i>, <i>Dmrt1</i>, and <i>Amh</i> were significantly inhibited. Our study cloned the full length of ERs and analyzed their structures and expressions, laying a foundation for the further study of the effect of estrogen on sex determination.