Figure 2. Bisulfite sequencing analysis of the IG-DMR (CG4 and CG6) and the MEG3-DMR (CG7), using leukocyte and placental genomic DNA samples. Filled and open circles indicate methylated and unmethylated cytosines at the CpG dinucleotides, respectively. Upper part: structure of CG4, CG6, and CG7. Pat, paternally derived chromosome; Mat, maternally derived chromosome. The PCR products for CG4 (311 bp) harbor 6 CpG dinucleotides and a G/A SNP (rs12437020), those for CG6 (428 bp) carry 19 CpG dinucleotides and a C/T SNP (rs10133627) and those for CG7 (168 bp) harbor 7 CpG dinucleotides. Lower part: the results of cases 1, 2, 4 and a control subject. Each horizontal line indicates a single subcloned allele. The control data represent the methylation patterns obtained with a leukocyte genomic DNA sample extracted from a single subject heterozygous for the G/A SNP (rs12437020) (body) and those obtained with a pooled DNA sample consisting of an equal amount of genomic DNA extracted from three control placentas homozygous for that SNP.