Figure 1. CpG site map of the human collagen 1(I) gene (COL1A1) gene. The first exon is indicated by the open rectangular box. The CpG sites are shown by the short vertical lines below the map. The three areas examined in the present study are indicated below the CpG sites by dark rectangular bars. The numbers on the map show the location of nucleotides when the initiation site for transcription is designated as +1.