Complete male-to-female sex reversal in mice lacking the miR-17~92 cluster [scRNA-seq]
The deletion of a single miRNA cluster, miR-17~92, is sufficient to induce primary sex reversal in XY mice. The expression of the testis determining gene, Sry, is delayed in embryonic XY miR-17~92 knockout gonads, which immediately activate the ovarian genetic program. Single cell RNA-seq analysis shows that Sertoli cell differentiation is highly reduced, delayed and unable to trigger testis differentiation. Consistent with the well-known role of miRNAs in gene regulation, the expression of target genes of miR-17~92 is not stabilized in XY mutant gonads at E11.5, affecting, in turn, the fine regulation of large gene networks involved in mammalian sex determination. Our results reveal that the miR-17~92 cluster is a novel sex-determining factor that modulates several gene networks required for accurate timing of Sry expression and Sertoli cell differentiation during testis determination and early differentiation. Overall design: bulk RNA-seq, single cell RNA-seq as well as IF and other characterizations of a transgenic mice for miR-17~92 cluster