Tissue-specific DNA methylation is conserved across species and driven by primary sequence conservation

Tissue specific differentially methylated regions (DMRs) have been shown to play important roles in tissue specification, but little is known about the conservation pattern of genome-wide DNA methylation distribution that encodes tissue specifity. Using a comparative approach, we identified and compared the tissue-specific DNA methylation patterns of the rat against that of mouse and human across three common tissue types. We found that 10%-40% of this tissue-specific DNA methylation pattern is conserved, and this epigenetic onservation is associated with the conservation of tissue specific TFBS.