MECP2/Mecp2 expression is known to be regulated by REs found within its promoter and intron 1. The altered MeCP2 expression in autistic patients and in mouse brains subjected to stress is correlated with increased MECP2/Mecp2 promoter methylation [2,12,13,18-20]. Therefore, we hypothesized that DNA methylation at the Mecp2 promoter and intron 1 might impact Mecp2 isoform-specific expression. For DNA methylation analysis by bisulfite pyrosequencing, we selected three regions within the Mecp2 promoter (named R1 to R3, hereafter) and three regions within the intron 1 (named R4 to R6, hereafter) (Figure 1B). These regions harbored different numbers of CpG sites; promoter regions R1: CpG island contains 13 CpG sites; R2: 4 CpG sites; R3: 2 CpG sites, and intron 1 regions R4: 1 CpG site; R5: 1 CpG site; and R6: 2 CpG sites.
