Fig. 1

The methylation sites captured in our skeletal muscle samples using reduced representation bisulfite sequencing technology were mapped in the context of both gene regions (a) and CpG island features (b). The regions were defined using UCSC browser refGene and CpG island tracks (see the “Methods” section). The promoter region was defined as 1000 bp (basepairs) upstream of the transcription start site (TSS); untranslated region (UTR); CpG island is 200–3000 bp stretch of DNA with a C + G content of 50 % and observed CpG/expected CpG in excess of 0.6; North (N) and South (S) shores flank the CpG island by 0–2000 bp; the North (N) and South (S) shelf flank the shores by 2000 bp (2000–4000 bp from the island)