Epigenetic regulation of mRNA N6-methyladenosine modifications in mammalian gametogenesis.

N6-methyladenosine (m6A) is the most prevalent epigenetic modification of mRNAs and broadly influences various biological processes by regulating post-transcriptional gene expression in eukaryotes. The reversible m6A modification is catalyzed by methyltransferases, METTL3 and METTL14 (writers), removed by the demethylases FTO and ALKBH5 (erasers) and recognized by m6A-binding proteins, namely the YTH domain-containing family of proteins (readers). Both m6A modification and the related enzymes are involved in the regulation of normal gametogenesis and embryonic development in many species. Recent studies showed that loss of m6A compromises gamete maturation, sex hormone synthesis, fertility and early embryonic development. In this review, we have summarized the most recent findings on the role of mRNA m6A modification in mammalian gametogenesis to emphasize the epigenetic regulation of mRNA in the reproductive system.