Abstract
Simple SummaryPelodiscus sinensis is an important aquatic economic species in China with sexual dimorphism. All-male breeding is becoming a research hotspot. Here, comparative transcriptome analyses of female, male, and pseudo-female gonads were performed. We found that the differences between males and pseudo-females were mainly related to steroid hormone synthesis at the transcriptome level. When it comes to the sox family genes, sox3 may have a role in the process of sex reversal from male to pseudo-female, when sox8 and sox9 were inhibited by exogenous estrogen.The Chinese soft-shelled turtle Pelodiscus sinensis shows obvious sexual dimorphism. The economic and nutrition value of male individuals are significantly higher than those of female individuals. Pseudo-females which are base to all-male breeding have been obtained by estrogen induction, while the gene function and molecular mechanism of sex reversal remain unclear in P. sinensis. Here, comparative transcriptome analyses of female, male, and pseudo-female gonads were performed, and 14,430 genes differentially expressed were identified in the pairwise comparison of three groups. GO and KEGG analyses were performed on the differentially expressed genes (DEGs), which mainly concentrated on steroid hormone synthesis. Furthermore, the results of gonadal transcriptome analysis revealed that 10 sex-related sox genes were differentially expressed in males vs. female, male vs. pseudo-female, and female vs. pseudo-female. Through the differential expression analysis of these 10 sox genes in mature gonads, six sox genes related to sex reversal were further screened. The molecular mechanism of the six sox genes in the embryo were analyzed during sex reversal after E2 treatment. In mature gonads, some sox family genes, such as sox9 sox12, and sox30 were highly expressed in the testis, while sox1, sox3, sox6, sox11, and sox17 were lowly expressed. In the male embryos, exogenous estrogen can activate the expression of sox3 and inhibit the expression of sox8, sox9, and sox11. In summary, sox3 may have a role in the process of sex reversal from male to pseudo-female, when sox8 and sox9 are inhibited. Sox family genes affect both female and male pathways in the process of sex reversal, which provides a new insight for the all-male breeding of the Chinese soft-shelled turtle.
Highlights
Pelodiscus sinensis, known as the Chinese soft-shelled turtle, is widely distributed in many freshwater areas, such as rivers and lakes in China, Korea, Russia, Thailand, Vietnam, and Japan [1]
The clean reads were aligned to the reference genome of P. sinensis, and the results showed that 67.34–72.69% of the clean reads were successfully mapped (Table 2)
In this study, gonadal transcriptomic differences between E2-induced pseudo-female, male, and female P. sinensis were investigated, and sox family genes were analyzed after E2 treatment
Summary
Pelodiscus sinensis, known as the Chinese soft-shelled turtle, is widely distributed in many freshwater areas, such as rivers and lakes in China, Korea, Russia, Thailand, Vietnam, and Japan [1]. This turtle shows obvious sexual dimorphism: males have a larger size, faster growth rate, and wider and thicker calipash than females. Sex-specific markers have been developed to accurately identify the genetic sex of a turtle by using RAD-Seq technology [1]. These studies suggest that genetic sex determination can be used for P. sinensis. It is important to study the sex determination mechanism of P. sinensis for the all-male aquaculture of this species
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
