Figure 2

Proportion of methylation and variations at each CpG site within Alu elements. The average proportion of methylation (CpG), deamination of CpG on the antisense strand (TpA), demethylation and deamination of CpG on the sense strand (TpG), and other variations at each CpG site among a total of 427 bisulfite clones from 14 tested gastric samples is illustrated (A). Maintenance, deamination on the sense strand (TpG) and antisense strand (CpA) at each CpG site were analyzed based on 56 tested clone sequences from a gastric mucosa sample without bisulfite modification (B) and on 476,152 copies of Alu elements extracted from the NCBI database of the human genome (C) as described bioinformatically (Ref. [13]).