Enrichment of P-TEFb kinase at the β-globin LCR and promoter region in differentiating MEL cells and alterations in H3ac and H3K4me3. (A-C) Chromatin was prepared from MEL cells before and after 4 days of 2% DMSO treatment. ChIP was performed with antibodies to (A) Cdk9 or (B) CycT1. Necdin served as a negative control. Data are mean ± SEM. (C) Antibodies to acH3 or H3K4me3 were used in ChIP and graphed together by setting the highest value obtained with each antibody equal to 1. Lines represent AcH3; and bars, H3K4me3.