Figure 2.

Defects in cellular proliferation and accelerated senescence in mIno80^Δ/Δ MEFs. (A) 3T3 proliferation assay of primary MEFs of the indicated genotypes either untreated or treated with 4-HT for 48 h. Three independent cell lines in each genotype were used. (B) Representative images of immunostaining with anti-BrdU antibody for 4 h after BrdU incorporation. (C) Quantification of the percentage of cells stained with anti-BrdU antibody from three independent cell lines per the indicated genotype either untreated or treated with 4-HT. Error bars represent s.e.m. and the Student's t-test was used for statistical analysis. (D) Representative images of primary MEFs stained with X-gal to detect SA-β-galactosidase activity (upper panels) and quantification of the percentage of cells with SA-β-galactosidase activity in CAG-CreER; mIno80^F/F MEFs with or without 4-HT treatment at passages 3 and 4 (lower panel). Error bars represent s.e.m. and asterisks indicate statistically significant differences (^*P < 0.05; ^**P < 0.005, Student's t-test). (E) Immunoblot analysis for mIno80, p21, PCNA, and γ-tubulin levels in primary MEFs at passage 3. Data from three independent mIno80^+/+ (lanes 1-3) and CAG-CreER; mIno80^F/F (lanes 4-6) MEFs either untreated or treated with 4-HT are shown.