Figure 2

DNA methylation statuses of the S-DMRs (species-specific differentially methylated regions) in four great ape species. (a) The DNA methylation levels of the 16 S-DMRs in peripheral blood leukocytes from humans (blue), chimpanzees (red), gorillas (green) and orangutans (purple) are shown. The S-DMRs with human-specific methylation changes and those with chimpanzee-specific methylation changes are indicated at the top. Asterisks mark the S-DMRs that could not be analyzed because of the species-specific deletion or insertion. (b) A phylogenetic tree based on the methylation data is shown. A hierarchical cluster analysis was performed with the methylation data from the 16 S-DMRs based on the neighbor-joining method using the R function hclust. The length of each vertical branch is proportional to the degree of difference in DNA methylation. (c) The numbers of human-specific (blue) and chimpanzee-specific (red) nucleotide changes identified by sequence alignment are shown for chimpanzee-specific (S-DMR 10) and human-specific S-DMRs (S-DMRs 2, 6, 3, 4, 12 and 16).