Figure 2.

Sensitivity of lymphocytes from noxa^−/−puma^−/− mice to apoptotic stimuli in culture. (a) Purified immature CD4⁺8⁺ thymocytes from wt, noxa^−/−, puma^−/−, noxa^−/−puma^−/− or p53^−/− mice were cultured for 8 h in the presence of dexamethasone (Dex, 1 μM) or for 24 h with phorbol 12-myristate 13-acetate (PMA, 10 ng/ml) or following γ-irradiation (1.25 or 5 Gy). Immature pro-B/pre-B cells (B220⁺sIg⁻) sorted from the bone marrow (b) or mature T cells (Thy-1⁺) sorted from the lymph nodes (c) of wt, noxa^−/−, puma^−/−, noxa^−/−puma^−/− or p53^−/− mice were cultured for 24 h following γ-irradiation (5 Gy). Viability of unstimulated cells of each type did not differ significantly between genotypes at these times. Data points represent means±S.D. of cells from 3–5 mice of each genotype. The percentage of viable noxa^−/−puma^−/− thymocytes remaining after treatment with 5Gy γ-radiation was significantly greater than for puma^−/− thymocytes treated with the same dose (P=0.032) and was not significantly different to the number of viable p53^−/− thymocytes. For a detailed kinetic analysis see Supplementary Figure 1