Undifferentiated hematopoietic cells have more open and dynamic chromatin than differentiated cells. (A) Levels of active (Me-H3K4) and repressive (Di-Me-H3K9) histone modifications and acetylation of histones (Ac-H3K9/14, Ac-H4) were compared at different stages in human (left row) and murine (right row) hematopoietic cells. (B) Protein expression levels of each indicated histone-modifying enzymes from human (left) and murine (right) hematopoietic cells. (C-D) Pulse-chase labeling of histone acetylation in lineage-negative (Lin−) and lineage-positive (Lin+) murine bone marrow cells (C) and in human CD34+ and CD34− cells (D). (Top panels) Autoradiography of immunoprecipitations using the antibodies as indicated from 106 input cells. Inp indicates input cells; IgG, immunoprecipitation with isotype IgG; Ac-H4, immunoprecipitation with antibody against acetylated H4. (Bottom panels) Immunoblots using antibody against total form of H4 from 106 input cells.
