Fig. 5. Specific hypomethylation of L1 promoter of active and inactive source elements.

(A and B) After bisulfite treatment of DNA and PCR amplification of L1 promoter regions composing the six most frequently active source elements, massively parallel sequencing was undertaken.The two most commonly observed haplotypes for each sample are depicted, with open circles representing CpG dinucleotides that are unmethylated and solid circles representing methylated CpG dinucleotides. The fraction of reads reporting each haplotype is shown on the right. Green circles on the left indicate which samples showed transductions derived from that source element; red circles indicate samples without activity of that source element. Asterisks after the sample name indicate tumor samples; those without asterisks are matched normal samples.