miR-202 drives medaka fertility by targeting antagonistic Yap-dependent transcriptional regulators tead3b and vgll4b in a sex-dependent manner

How miRNAs can sometimes drive major organism-level phenotypes by targeting a single gene and by triggering limited changes in mRNA levels remains poorly understood, especially in vertebrates. In medaka, the knockout of miR-202-5p, a gonad-specific miRNA in vertebrates, leads to impaired male and female fertility, including drastically reduced egg production and low developmental success. Here we show that miR-202-5p drives gamete formation by targeting antagonist Yap-dependent transcriptional regulators tead3b and vgll4b in a sex-dependent manner. Disruption of the miR-202-5p binding site in the 3UTR of tead3b, but not vgll4b, results in a significant decrease in female fertility. In contrast, disrupting miR-202-5p target site in the 3UTR of vgll4b, but not tead3b, results in impaired male fertility. In females, 3D ovary imaging and RNA-seq analysis of isolated ovarian follicles revealed that disrupting miR-202-5p binding to the 3 UTR of tead3b results in a polycystic ovarian syndrome (PCOS)-like phenotype and the expression of many PCOS-associated marker, including androgen signaling and estrogen metabolism genes. In males, disrupting miR-202-5p binding to the 3UTR of vgll4b triggers severe phenotypes, including reduced sperm motility and abnormal testicular development. No effects on sex ratio were observed, indicating that miR-202-5p drives gamete formation by regulating mechanisms acting down-stream of the sex-determining cascade. The analysis of miR-202-5p target sites in 3 UTRs suggests long-term conservation of antagonistic TEAD and VGLL targeting across vertebrate species, including mammals. Together, our results show that miR-202-5p drives fertility by leveraging antagonistic Yap-dependent transcriptional regulators in a sex dependent manner.