Profiles and roles of N6-methyladenosine modification in bovine oocyte maturation [MeRIP]
The quality of bovine oocytes is crucial for in vitro embryo production technology, thus it is essential to study the mechanisms of oocyte maturation. N6-methyladenosine (m6A) modification plays a key role in gametogenesis and embryonic development. However, the dynamic landscape and functional roles of m6A modification during bovine oocyte maturation remain unclear. We conducted transcriptome-wide m6A landscape analysis on bovine oocytes at the GV and MII phases using MeRIP-seq and RNA-seq technologies. We identified a total of 6,323 differential m6A peaks in the two groups of oocytes, with 4,422 m6A peaks being significantly upregulated and 1,901 m6A peaks significantly downregulated. The combined analysis of MeRIP-seq and RNA-seq identified 262 genes with significant differences in both methylation modification and transcriptome levels. GO and KEGG enrichment analyses of these genes revealed significant enrichment in biological processes and signaling pathways such as endocytosis, thermogenesis, ribosome, cellular metabolism, Apelin signaling pathway, and HIF-1 signaling pathway. Finally, we examined the roles of m6A modification in bovine oocyte maturation. The results showed that inhibition of m6A modification affects nuclear and cytoplasmic maturation of oocytes. Our results reveal the m6A modification profile during bovine oocyte maturation. Furthermore, we found that inhibition of m6A modification leads to meiotic failure. These results provide a theoretical basis for studying the function of RNA modification in oocyte maturation. Overall design: GV stage and MII stage bovine oocytes cultured in vitro were collected for MeRIP-seq and RNA-seq