Histone modifications across the β-globin locus in MEL745a and FDCP-Mix cells. The murine β-globin locus is depicted to scale as a line at the top, with the 4 developmentally regulated β-globin genes labeled over black arrows, and exons represented by black bars on the line. Unlabeled, thicker black bars on the line represent β-globin pseudogenes. HS2 indicates hypersensitive site 2 of the locus control region (LCR). Black bars below the line depict the locations of PCR amplimers used in the ChIP assay, which is shown in turn in bar graph format for each of the antibodies used for IP. (A) Quantitative RT-PCR of combined β1- and β2-globin mRNA expression levels relative to 18s mRNA in FDCP-Mix, and in both uninduced (Un-Ind.) MEL745a and MEL745a induced with 2% DMSO for 72 hours (Ind.). (B) Fold induction of β1- and β2-globin mRNA expression levels in MEL745a on culture in 2% DMSO for 72 hours, relative to uninduced MEL745a. (C) Bar graph depicting H3Ac and (D) H3K4 dimethyl enrichment levels, relative to inactive gene loci (“ChIP”), in both uninduced (Un-ind.) and induced (Ind.) MEL745a. The positions of each bar correspond to the positions of the corresponding amplimers shown to scale at the top. (E) H3K4 trimethyl enrichment levels, relative to inactive gene loci, for uninduced and induced MEL745a. (F) H3Ac and H3K4 dimethyl enrichment levels for FDCP-Mix.