FIGURE 8.
Induced Brpf1 inactivation causes defective cell growth, cell cycle control and histone H3 acetylation. Brpf1f/f;ER-Cre MEFs derived from E15.5 embryos were treated with vehicle and 4-hydroxytamoxifen to prepare Brpf1f/f and Brpf1−/− MEFs, respectively. A, MEF growth was monitored by IncuCyte for 7 days. The difference between Brpf1f/f and Brpf1−/− MEFs became significant at day 4. B and C, Brpf1f/f and Brpf1−/− MEFs were stained with propidium iodide (PI) and analyzed by flow cytometry. Representative graphs were shown (B), and the ratio of different cell cycle phases was quantified (C). Experiments in A–C were repeated with three batches of MEFs isolated from three independent litters. *, p < 0.05; **, p < 0.01. D, immunoblotting analysis of Brpf1f/f and Brpf1−/− MEF extracts with antibodies specific to histone H3, its acetylated forms (H3K14ac, H3K9ac, and H3ac), and Hbo1 as indicated. Histone H4 acetylation at Lys-16 and the γH2AX level remained unaltered in mutant MEF extracts (data not shown).