DNA methylation dynamics during yak adipocyte differentiation

In mammals, epigenetic modifications involving DNA methylation are necessary for the completion of the cell differentiation process. However, the global DNA methylation landscape and its dynamics during yak adipocyte differentiation remain unexplored. Here, we performed whole-genome bisulfite sequencing (WGBS) to asses DNA methylation in yak preadipocytes and adipocytes, combining these results with those of our previous studies on changes in chromatin accessibility and gene expression during yak adipogenesis. The results showed that CG methylation levels were lower in promoter than in exon and intron, and gradually decreasing from the distal regions to transcription start site (TSS). There was a significant negative correlation between CG methylation levels located in promoter and gene expression levels. The 46 genes shared by CG differentially methylated regions (DMRs) and differential chromatin accessibility were significantly enriched in Hedgehog and PI3K-Akt signaling pathways. ATAC-seq peaks with high chromatin accessibility located in both promoter (≤ 2 kb from TSS) and distal (> 2 kb from TSS) regions corresponded to low methylation levels. Taken together, these findings demonstrated that DNA methylation and its interactions with chromatin accessibility regulate gene expression during yak adipocyte differentiation, contributing to the understanding of mechanisms of various epigenetic modifications and their interactions in adipogenesis.