Integrated transcriptomic and proteomic analyses reveal sex-biased molecular regulation in the gonads of Rana dybowskii with implications for female-biased breeding

The molecular mechanisms underlying female sex determination and differentiation have long been a major research focus in aquaculture. The Dybowski`s frog ( Rana dybowskii ), an economically important species in China, exhibits pronounced sexual dimorphism, with females possessing much higher economic value than males. In this study, integrated transcriptomic and proteomic analyses were applied to characterize sex-biased molecular profiles of female and male gonads in R. dybowskii . A total of 4112 proteins were identified in ovaries and 6897 in testes, among which 2118 were differentially abundant between the sexes. Functional enrichment analyses indicated that sex-biased proteins were mainly associated with steroid hormone metabolism, transcriptional and post-transcriptional regulation, energy metabolism, and cytoskeletal organization, reflecting distinct regulatory and metabolic features of ovarian and testicular development. Several gonadal development–related regulators, including SF-1, AKR1C1, HPGDS, HDAC2, ADAR, and EWSR1, exhibited pronounced sex-dependent expression patterns, while integrated transcriptome–proteome analysis revealed partial concordance and notable discordance between mRNA and protein levels, suggesting an important contribution of post-transcriptional control. Together, these findings provide a comprehensive multi-omics framework for understanding sexual dimorphism in R. dybowskii and identify candidate molecular targets that may facilitate the development of female-biased breeding strategies in amphibian aquaculture.