Figure 3.

Sensitivity of embryonic fibroblasts from noxa^−/−puma^−/− mice to apoptotic stimuli. E1A-expressing MEF from wt, noxa^−/−, puma^−/−, noxa^−/−puma^−/− or p53^−/− embryos were cultured for 24 h in simple medium with (a) or without serum (b), or were exposed to 10 μg/ml (c) or 100 μg/ml (d) etoposide or γ-irradiation (50 Gy) and analysed after 24 (e) or 72h (f). Data points represent means±S.D. of cells from 3-5 independent embryos of each genotype. The percentage of viable noxa^−/−puma^−/− E1A-MEF remaining after treatment with 10 μg/ml etoposide was significantly greater than for puma^−/− E1A-MEF treated with the same dose (P=0.012). For a detailed kinetic analysis see Supplementary Figure 2