Integrative Analysis of Whole-Genome Bisulfite Sequencing and RNA-Seq in Skeletal Muscle of Xin'anjiang Water Buffalo

Xin'anjiang water buffalo (XAJB) is crucial for meat production and agricultural activities in Anhui Province of China. To generate hypotheses regarding how DNA methylation might correlate with transcriptional differences in skeletal muscle, WGBS and RNA-seq were performed on three BF and three BM adult XAJB. The results revealed 31,333 differentially methylated cytosines (DMCs), 1961 differentially methylated regions (DMRs), and 230 differentially expressed genes (DEGs) in skeletal muscle between the two groups. The qRT-PCR results of ten DEGs (COL1A1, THBS1, SLITRK4, VIPR2, IGFBP6, WIF1, MMP16, LMOD3, NPR3 and MYLK4) enriched in protein digestion and absorption pathway, PPAR signaling pathway, ECM-receptor interaction pathway or PI3K-Akt signaling pathway were consistent with the RNA-seq results. Most methylation changes occurred in CG context, and sixteen genes were predicted as dual differential genes in both methylation and transcriptome. Moreover, CG methylation showed a significant negative correlation with gene expression within the 2 kb upstream region (rho = -0.42, p < 0.001). Given the limited number of animals examined, additional investigations with expanded cohorts are essential to verify the association between the methylome and transcriptome signatures underlying skeletal muscle in XAJB.