FIG. 5.
Epigenetic analysis at fetal and adult globin promoters in e12.5 fetal livers. (A) ChIP assays performed on e12.5 fetal livers from two PBGDAγ-YAC lines (PY367 and PY465) (white bars) (n = 9 to 13) and the control β-YAC line (black bars) (n = 7), using specific antibodies for histone H3 (H3), the acetylated forms of histone H3 (H3ac) and H4 (H4ac), and the K4-dimethylated form of histone H3 (H3me). Enrichment of histone acetylation/methylation (y axis), determined at the γ-globin promoters (for γ, positions −158 to +53; and for PBGDAγ, positions −167 to +47) and at the β-globin promoter (positions −146 to +36) for β-YAC and PBGDAγ-YAC lines, is depicted in the histogram as the median of ratios relative to the control gene Zfp37 ± the interquartile range, normalized on total H3 for both H3ac and H3me modifications. The P values were determined by Kruskal-Wallis and Mann-Whitney tests. *, P < 0.01; **, P < 0.002; ***, P < 0.0001. (B) γ- and β-globin promoter DNA methylation status was assessed in e12.5 fetal livers from two PBGDAγ-YAC lines (PY418 and PY367) (n = 4 [2/line]) and the control β-YAC line (n = 3). The histograms show CpG dinucleotide methylation at each locus coordinate, with localization relative to the +1 initiation site indicated in parentheses, as percentages ± SD of the undigested methylated HpaII (H), HhaI (Hh), and BsaAI (B) sites from EcoRI (E) globin promoter fragments. The P values were determined by Student's t test. *, P < 0.002.