Abstract:
In order to explore the appropriate method of feminization and 17β-estradiol doses for male channel catfish, artificial compound feed was used as 17β-E
2 vector to feed catfish larvae continuously for 27d. The growth data and survival rate of catfish in each group were measured and counted at 60 dahs, the sex reversal rate was also calculated in combination with the genetic sex identification results. Furthermore, the ovarian development of XX and XY females in each group was compared and analyzed based on the H & E staining of ovary tissue paraffin sections. Finally, 17β-E
2 contents in gill, heart, liver, kidney, ovary and muscle tissues of XY females in each group were detected and compared with control XX females at 270 dahs. In addition, qRT-PCR was used to detect the expression levels of
foxl2 and
dmrt1 in XX and XY female ovaries at 270 dahs. The results showed that the proportion of XY females and the number of oocytes in each group were increasing with 17β-E
2 doses. The weight and body length of female fish in each group first increased and then decreased with the increase of 17β-E
2 doses. The survival rate was no significant in each group. The content of 17β-E
2 in ovary was positively correlated with 17β-E
2 doses, while no differences were observed in gill, heart, liver, kidney and muscle of female fish. The expression levels of
foxl2 gene increased in XY females, while
dmrt1 gene decreased in XY females. This study established 17β-E
2 induced feminization of XY male channel catfish, and laid a solid foundation for the subsequent cultivation of new male channel catfish varieties.