ChIP analysis of mouse and human β-globin genes and promoters. Immunoprecipitated samples were subjected to duplex PCR analysis with one primer set specific for human or mouse β globin regions and a second primer set specific for ZFP37 (ZFP) or pax6 gene. The level of enrichment of globin regions relative to the control regions and input samples is represented by bars, with their corresponding SEM deviations. □ indicates progenitors; and ▪, erythroid cells. (A-B) ChIP analysis of ln2 HPCs and erythroid cells. Either βmaj or the transgenic huβ promoter was analyzed by PCR-based ChIP assay. X-axis indicates antibodies used for ChIP assays. AcH3 indicates antiacetylated H3; AcH4, antiacetylated H4; MeK4, antidimethylated H3; PhH3, antiphosphorylated H3; and H3, antinonmodified histone H3. (C) ChIP analysis of huβ promoter in human HPCs and erythroid cells. For ChIP analysis anti-AcH3 or AcH4 Abs were used. (D) Schematic representation of the huβ region; huβ exon 1 and 2 are indicated by gray boxes and amplicons are shown by dotted lines. (E) huβ5, huβ1 and (F) human Ψβ regions in ln2 (tg-huβ5, tg-huβ1, and tg-psβ) and human (huβ5, huβ1, and psβ) HPCs and erythroid cells were investigated by PCR-based ChIP assays performed with anti-AcH3 Abs.