YTHDF2 is essential for spermatogenesis and fertility by mediating a wave of transcriptional transition in spermatogenic cells

摘要

The dynamic and reversible regulation roles of m6A modification and the characterization of m6A readers have provided new insights into spermatogenesis at the post-transcriptional level.YTHDF2,as an meA reader,has been reported to mediate the meA-containing transcript decay during the mouse oocyte maturation,embryonic stem cell differentiation,neural development,and zebrafish maternal-to-zygotic transition.However,the roles of YTHDF2 in mammalian sper-matogenesis are uncertain.Here,we generated germ cell-specific Ythdf2 mutants (Ythdf2-vKO)at a C57BL/6J background and demonstrated that YTHDF2 is essential for mouse spermatogen-esis and fertility.Ythdf2-vKO provides oligoasthenoteratozoospermia phenotype with increased apoptosis in germ cells.High-throughput RNA-seq analysis showed that a group of mRNAs is upregulated in Ythdf2-vKO mouse testis;further analysis and MeRIP-qPCR data showed that most of the upregulated genes in Ythdf2-vKO mouse testis are modified with m6A and are YTHDF2 candidate binding genes.Interestingly,RNA-seq analysis combined with our previous single-cell transcriptomics data of mouse spermatogenesis pointed out the failure of a wave of transcript transition during the spermatogenesis of Ythdf2-vKO mice,which was confirmed by gene expres-sion analysis using qPCR of diplotene spermatocytes and round spermatids obtained through fluorescence-activated cell sorting.Our study demonstrates the fundamental role of YTHDF2 dur-ing mouse spermatogenesis and provides a potential candidate for the diagnosis of male infertility with the oligoasthenoteratozoospermia syndrome.