Figure 4
DNA methylation level distributions of five levels of gene expression.
The DNA methylation profile in the gene regions (TSS, gene body and TTS) were shown by the reads that were aligned on a unique locus in the genome. In upstream and downstream 2 kb regions, the regions were split into 20 non-overlapping windows and the average alignment depth was calculated for each window. In the gene body, each gene was split into 40 equal windows and the average alignment depth was calculated for each window. The Y-axis represents the average of the normalized depth for each window. Genes were divided into five groups according to expression levels: lowest-level expressed genes (silent genes), lower-level expressed genes), middle-level expressed genes, higher-level expressed genes and highest-level expressed genes (house-keeping genes). Each line in the figure represents the DNA methylation level of different expression groups. For both fetal and adult bovine, the red line indicates that genes with the lowest expression level had a relatively low methylation level, the blue line indicates that genes with a middle expression level had a middle methylation level and the green line indicates that genes with the highest expression level had a relatively high methylation level. The DNA methylation profile in and around gene bodies were compared across these five gene expression levels. (A): fetal bovine; (B): adult bovine.
