Potential antagonistic relationship of and genes in WNT4 pathway to regulate the sex differentiation in Chinese giant salamander ().

Farmed chinese giant salamander () was an important distinctive economically amphibian that exhibited male-biased sexual size dimorphism. and genes antagonize each other in Wnt4 signal pathway to regulate mammalian gonadal differentiation has been demonstrated. However, their expression profile and function in are unclear In this study, we firstly characterized and genes expression in developing gonad. Results showed that expression level was higher in testes than in ovaries and increased from 1 to 6 years while expression was higher in ovaries than in testes. hybridization assay showed that both and genes expressed at 62 dpf in undifferentiated gonad, and gene was mainly expressed in spermatogonia and sertoli cells in testis while strong positive signal of was detected in granular cell in ovary. During sex-reversal, expression was significantly higher in reversed testes and normal testes than in ovaries, and opposite expression pattern was detected for When FH535 was used to inhibit Wnt/β-catenin pathway, expression of , was down-regulated. Conversely, expression of and were up-regulated. Furthermore, when were knocked down using RNAi technology, respectively. We observed that female biased genes were down regulated in ovary primordial cells after was knocked down, while the opposite expression profile was observed in testis primordial cells after was knocked down. These results suggested that and played an antagonistic role to regulate sex differentiation in the process of the gonadal development and provided a foundation for further functional characterizations. The data also provided basic information for genome editing breeding to improve the Chinese giant salamander farming industry.