ABSTRACT: The epididymis is an important component of the male reproductive system and a crucial site for sperm maturation. During the process of sperm maturation through the epididymis, the effective payload of SncRNA significantly changes, which may be related to epigenetic modifications. Unfortunately, the N6 Methyladenosine (m6A) modification profile of the epididymis has not yet been established. In this study, the MeRIP seq combined with RNA seq method was used to analyze the m6A modification levels in the head, body, and tail of yak epididymis. It was found that the level of m6A in the epididymis significantly increased, and differentially methylated RNAs (DMRs) in the proximal end of the epididymis were significantly enriched in Gap junction, ErbB signaling pathway, and mTOR signaling pathway, participating in cell communication and sperm maturation processes. In the distal epididymis, DMRs are enriched in Apoptosis, FoxO signaling pathway, PI3K Akt signaling pathway, and TNF signaling pathway, which are involved in sperm autophagy, oxidative stress, and sperm maturation. In addition, we identified key genes with significant changes in m6A levels but no differences in RNA levels, including YY1 associated factor 2 (YAF2), Fork head box J2 (FOXJ2), and Fork head box O1 (FOXO1), suggesting that these genes are modified by m6A to affect translation processes and participate in sperm maturation. In summary, our study established an m6A map of the epididymis, which is beneficial for further understanding the maturation process of sperm and revealing more information related to male infertility.
