Fig. 5.

An underlying genetic basis for species differences in DMRs. A 7,500-bp human region was mapped to the mouse genome. The x-axis shows an index so that mapped bases are on top of one another. (Top) Methylation profiles for each human sample. As in Fig. 1, the dashed lines represent the individuals, and the solid lines represent the tissue averages. (Middle) The same plot for mouse. (Bottom) Ticks representing CpG locations for human and mouse. The orange ticks represent CpGs that were conserved. The curves represent CpG counts in a moving window of size 200 bases. Note that the lack of CpGs in the mouse at the beginning of the regions is associated with a difference in methylation patterns between species. Shown is LHX1, a transcriptional regulator essential for vertebrate head organization and mesoderm organization. Note the DMR in human that is not in mouse on the left of the TSS. The human has gained CpGs at a CpG island shore (orange tick marks). In contrast, both species have a moderate CpG count to the right of the TSS, and both have DMRs in this region.