Fig. 1

DNA methylation of promoter regions in crypts. a Unsupervised hierarchical clustering analysis of DMEPs in crypts. Each row indicates a differential methylation enrichment peak (DMEP)-related gene. Each column indicates a sample analyzed. Methylation levels range from unmethylated (green) to fully methylated (red), as indicated by the color legend at the top of the graph. C represents the control db/+ group; D represents the diabetic db/db group. b Mean of relative enrichment strength in DMEPs. Mean ± SE; n = 3; *P = 0.028 by t test. c Numbers of group comparison-related DMEPs. db/+_db/db represents the DMEPs more closely matching the promoter region for the db/+ group than that in the db/db group; and db/db_db/+ represents the DMEPs more closely matching the promoter region for the db/db group than that in the db/+ group. d Pie charts of high, intermediate, and low CpG-density promoters (HCPs, ICPs, and LCPs, respectively) indicate slight differences in the percentages of HCPs and LCPs between the two groups