The Influences Of DES And EE2on The Gonadal Development And Gametogenesis Of Yellow Catfish (Pelteobagrus Fulvidraco)

Endocrine disruptor chemicals (EDCs) can. seriously affect the reproductive development and sex ratio of the population. Ethinylestradiol (EE2) and diethylstilbestrol (DES) are the typical EDCs in the Three Gorges Reservoir Area. To assess the impact of EE2and DES Three Gorges Reservoir fish gonadal development and gametes, we selected the farmed fish in Yangtze River-yellow catfish (all-male) juveniles as subjects, and then treated EE2and DES (lOng/g and100ng/g,45days after hatching, feeding20days).The results showed that all treatment groups had apparent changes, such as:the gonadal development delayed even stopped; the germ cell apoptosis and the goand partially reversed. To study the possible regulatory mechanism, we cloned the full-length cDNA of Dmrtl, Cypl9a, Scp3by RT-PCR and RACE methods; the semi-quantitative PCR was used to study these genes expression patterns and expression changes after the treatment of EE2and DES. The results show that, Dmrtl expressed in male gonad, Cypl9a expressed in female gonad and Scp3both expressed in the male and female gonads. Semi-quantitative PCR analysis showed that DES and EE2both downregulate the Scp3expression.We hypothesized that Dmrtl and Scp3may be involved in the the yellow catfish male gonadal development and gametogenesis process; Cypl9a, may be involved in yellow catfish female gonadal development process; EE2and DES-induced catfish gonadal abnormalities may be caused by regulating the Scp3expression. In summary, the typical endocrine disruptors in the Three Gorges Reservoir Area-EE2and DES will seriously affect the the catfish normal male development process, and may result in males infertility, impairring reproductive function, or even partial reversal. In conclusion, DES and EE2can seriously affect the normal population structure of the species in the Three Gorges Reservoir Area.