Analyzing the gonadal transcriptome of the frog Hoplobatrachus rugulosus to identify genes involved in sex development

BackgroundThe tiger frog (Hoplobatrachus rugulosus) is listed as a national Class II protected species in China. In the context of global warming, the sex ratio of amphibians will be affected, and the development of the population will be limited. Therefore, considering the potential for a decrease in the number of amphibians, studying sex evolution and molecular regulation of gonadal development in H. rugulosus, phenomenon that are currently unclear, is of great significance.ResultsHere, H. rugulosus was used to explore the mechanisms regulating gonadal development in amphibians. Illumina HiSeq 3000 was used to sequence the gonadal transcriptome of male and female H. rugulosus at two growth stages to identify genes related to gonadal development and analyze expression differences in the gonads. This analysis indicated that cyp17 alpha, hsd3 beta, hsd11 beta 1, cyp19 alpha, and hsd17 beta 12 perform vital functions in sex development in amphibians. Specifically, the expression of cyp3 alpha, cyp17 alpha, hsd3 beta, hsd11 beta 1, sox2, sox9, sox30, soat, cyp19 alpha, hsd17 beta 12, and hsp alpha 1s was correlated with gonadal development and differentiation in H. rugulosus, as determined using the quantitative reverse transcriptase-polymerase chain reaction.ConclusionSignificant differences were found in the gonadal gene expression levels in H. rugulosus of both sexes, and we identified a steroid hormone synthesis pathway in this species and analyzed related gene expression, but the changes during sex differentiation were still unclear. To our knowledge, this report presents the first analysis of the H. rugulosus gonadal transcriptome and lays the foundation for future research.

Automated summary

The tiger frog is a protected species in China. This study identified key genes related to gonadal development in amphibians using Illumina HiSeq 3000 sequencing, laying the foundation for future research. Significant differences in gonadal gene expression levels in male and female tiger frogs were found.