Changing patterns of γ-globin promoter methylation during in vitro differentiation. (A) Percentage methylation of specific CpGs in the γ-globin promoters during in vitro differentiation. (B) Comparison of percentage methylation of the 3 CpGs upstream of the transcriptional start site to that of the 3 CpGs downstream of the start site. (C) Relative mRNA levels of DNMT genes during in vitro differentiation. Error bars indicate plus or minus 1 standard deviation.