Fig. 5. MacroH2A in reactivated lymphocytes. (a) Con A-activated lymphocytes from mouse spleen double-stained with antibodies against macroH2A and BrdU. (b) Nuclear proteins from resting (Con A -) and activated (Con A +) lymphocytes were stained with Coomassie (lanes 1, 2) and probed with antibodies against macroH2A (lanes 3, 4). (c) Fraction of proliferating, BrdU-positive lymphocyte nuclei (open columns) and fraction of nuclei with pericentromeric macroH2A distribution (solid columns), with standard errors. Lymphocytes were reactivated with Con A for 36 hours, pulsed with BrdU for 5 minutes and, at the times indicated, stained for macroH2A and BrdU. (d) Fraction of nuclei with pericentromeric macroH2A distribution. Lymphocytes were reactivated with Con A for 36 hours, then pulsed with BrdU for 1 hour [trichostatin A (TSA)] or 5 minutes (Na-but) and were incubated for 48 hours without histone deacetylase (HDAC) inhibitors (48), for the last 4 hours with 5 ng/ml TSA (TSA), or for last 24 hours with 2.5 mM Na-butyrate (Na-but). Cells were stained for macroH2A, and quantitated to reveal the distribution of macroH2A.