Chromatin immunoprecipitation analysis in primary erythroblasts and megakaryoblasts. ChIP experiments were performed on primary erythroblasts (A) and megakaryocytes (B). The Gata1 locus is shown on top with the Gata1 and Hdac6 genes depicted as black boxes. Hematopoietic and general DNaseI hypersensitive sites are indicated with gray and black arrows, respectively. At various points along the Gata1 locus (x-axis, coordinates in kilobases with respect to the Gata1 transcriptional start site), the degree of enrichment of acetylated histone H3 (AcH3) GATA1, SCL, and LDB1 (in panel A only; black bars) is shown. Amplicons corresponding to mHS−25/6, mHS−3.5, IE promoter, and mHS+3.5 are highlighted by gray stripes. The 2 bars at position mHS−25/6 represent amplicons for mHS−25 and mHS−26 individually (right and left bars, respectively). Experiments were performed at least twice and data from representative experiments are shown.