The transcription factor Sox30 is involved in Nile tilapia spermatogenesis.

Spermatogenesis is a complex process in which spermatogonial stem cells differentiate and develop into mature spermatozoa. The transcriptional regulatory network involved in fish spermatogenesis remains poorly understood. Here, we demonstrate in Nile tilapia that the Sox transcription factor family member Sox30 is specifically expressed in the testes and mainly localizes to spermatocytes and spermatids. CRISPR/Cas9-mediated sox30 mutation results in abnormal spermiogenesis, reduction of sperm motility, and male subfertility. Comparative transcriptome analysis shows that sox30 mutation alters the expression of genes involved in spermatogenesis. Further chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq), ChIP-PCR, and luciferase reporter assays revealed that Sox30 positively regulates the transcription of ift140 and ptprb, two genes involved in spermiogenesis, by directly binding to their promoters. Our data, taken together, indicate that Sox30 plays an essential role in Nile tilapia spermatogenesis by directly regulating the transcription of the spermiogenesis-related genes ift140 and ptprb.