Mutual exclusion of H3K27 and DNA methylation. H3K27 and DNA methylation data from figures 2 and 3 were redrawn to highlight the mutual exclusion of H3K27me3 and DNA methylation. (A) Modifications present at Rasgrf1 in wild type MEFs show that paternal DNA methylation (green) is largely even over the region, while maternal DNA methylation (red) is absent over the DMD but present upstream and downstream. Strikingly, H3K9me3 and H3K27me3 are perfectly confined to the DMD. (B) Modifications in the paternal allele in +/RepΔ mice. DNA methylation (black) is lost from the DMD and downstream, allowing encroachment of H3K27me3 into these regions (red). (0.15 MB TIF)