Epigenetic Effects and Potential Contributions of m6A Modification to Mammary Gland Development and Lactation of Dairy Goats Explored viaMeRIP-seq

To date, more than 170 chemical modifications have been identified in RNA. m6A (N6-methyladenine) RNA methylation is the most abundant form of mRNA modification in eukaryotes, playing an important role in RNA post-transcriptional processes. To investigate the function of m6A methylation modification in the development and lactation of dairy goat mammary glands, mammary gland tissue samples were collected in the early (20 days postpartum), peak (90 days postpartum), and late period (210 days postpartum) of three dairy goats. MeRIP-seq and RNA-seq were used to explore m6A methylation modification events. We identified 1638 differential peaks in the MeRIP-seq data across 1539 differentially methylated genes, which were enriched in ribosome biogenesis in eukaryotes, Toll-like receptor signaling pathway, TNF signaling pathway, MAPK, and other pathways related to mammary gland development and lactation. A conjoint analysis revealed that 179 common differential expressed genes were obtained, of which 150 were negatively regulated by their m6A modifications, while 5 common differentially expressed genes—PPARG, HSPA2, CDK5, ACTB and NOTCH3, were screened out in the two groups. In conclusion, m6A modification involves the pathways related to mammary gland development and lactation by modifying gene expression. This studyprovides new insights into m6A epigenetic regulation, mammary epithelial gene networks, and actionable molecular targets for high-value dairy product production and the breeding of new varieties.