Figure 2. Epigenetic stability of six imprinted DMRs.

DNA methylation was analyzed by deep bisulfite amplicon sequencing. The heatmaps show each CpG site in columns and individual sequenced reads in rows. Red: methylated, blue: unmethylated. Most heatmaps display a 50% methylation level, which is expected for imprinted DMRs in diploid cells. Exceptions are a loss of methylation at ICR1 (#B1), ICR2 (#P) and NESPAS (#42, #645, #B1, #P). CpG85 shows consistent gain of methylation, except for the control fibroblast sample. IG-DMR exhibits hypermethylation in both hESC lines, #42 and #645 and hypomethylation in the immortalized patient-derived fibroblast sample.