Fig. 4

Analyses of CpG islands and methylation of Sox9. a Structural features of the Sox9 sequence. The scaled horizontal line indicates the genomic DNA sequence, with the transcription start site (TSS) at zero; scales represent base pairs. Three CpG islands of Sox9 close to the TSS are indicated in the light blue area on top of the horizontal line. Vertical lines beneath the horizontal line indicate the distributions and densities of CpG sites. The light blue rectangular box indicates the location of the methylation peak signal region detected in the microarray and used in the bisulfite sequence analysis. b Promoter methylation microarray of Sox9 indicating hypermethylated promoters in the db/+ group (light blue bars). Values in brackets indicate the peak score that reflect the probability of positive enrichment and average P value scores. c, d Validation of Sox9 microarray results by bisulfite sequencing. Bar graphs indicating the proportion of methylated cytosines in CpGs within the regions analyzed. Ten bacterial colonies are detected per sample. Mean ± SE; *P < 0.05, **P < 0.01 by t test. IESCs intestinal epithelium stem cells