Abstract:Sex determination and differentiation in fish are not only influenced by genetic factors, but also controlled by environmental factors. Previous studies have shown that cortisol plays an important role in the feedback of environmental stress in fish. Fish hsd11b1l and hsd11b2 can regulate the concentration of cortisol. In this study, we cloned full-length cDNA of hsd11b1l and hsd11b2, and analyzed their sequence characteristics in Chinese tongue sole (Cynoglossus semilaevis). We then detected their spatiotemporal expression characteristics and expression patterns after temperature stress. The full-length cDNA of hsd11b1l was 1650 bp with 864 bp open reading frame encoding a predicted 287 amino acid protein. While the full-length of hsd11b2 was 4526 bp with 1209 bp open reading frame encoding 402 amino acid protein. The qPCR showed that the highest expression of hsd11b1l was within the liver and the expression level in the ovary was two-fold higher than that in testis. In particular, the expression level of hsd11b1l in the ovary was higher than in testis at the stages of 6 mpf and 3 ypf. The hsd11b2 was expressed mainly in the testis and expression level peaked in testis at 6 mpf. Conversely, expression of hsd11b2 was hardly detected in any stages of ovary development. In addition, we analyzed the expression patterns of hsd11b1l and hsd11b2 after high-temperature (28℃) treatment. The expression levels of hsd11b1l and hsd11b2 was significantly reduced in the gonads of males (P<0.05) after the high-temperature treatment for 2 months. For the acute high-temperature treatment (48 h), the expression of hsd11b1l significantly decreased in the gonads of both females and males (P<0.05), and the expression of hsd11b2 was only significantly down-regulated in the male testis (P<0.05). In this study, the expression patterns of hsd11b1l and hsd11b2 genes in the developmental stages of gonads affected by high temperature stress lays a foundation for understanding the relationship between temperature and sexual differentiation in Chinese tongue sole.
