Strand-specific methylation analysis of theρ-globin gene during development in chicken erythroid cells.

(A) Promoter, (B) exon 1 or proximal transcribed region, and (C) exon 3 or distal transcribed region. At least 4 CpG dinucleotides were quantitated for methylation. Error bars indicate the standard error of the mean. (D) Progressive methylation of the promoter (P), exon 1, and exon 3 regions on the coding (top) strand during development.