tDMR validation. Six tDMRs were randomly selected and subjected to bisulphite sequencing analysis. a). tDMR status based on pair-wise comparisons of the log2 MeDIP enrichment ratios of the indicated tissues/cell types. Black boxes represent tDMRs that are more methylated in sample 1 of the comparison and grey boxes represent tDMRs that are more methylated in sample 2 of the comparison. b). Absolute DNA methylation values of individual CpG sites in tDMRs based on bisulphite sequencing analysis. Because of assay and or technical limitations, bisulphite data could only be obtained for about 50% of the CpG sites involved in the putative tDMRs. Each square represents a CpG site. The colour code indicates methylation values as calculated by ESME (see Methods). Grey squares indicate CpG sites for which no data could be obtained. Based on this analysis, bisulphite data essentially agree with array data in all cases. Numbers of tDMRs correspond to tDMR numbers in table 2.