Effects of Bcl-2 overexpression on adult mice and cells. (A) In vivo survival curves of Bcl-2 transgenic mice and nontransgenic littermates. Adult mice of 7 to 22 weeks of age were subjected to a split dose of γ-irradiation of 10.5 Gy. Survival of both Ln 479 (shown) and Ln 2 (not shown) transgenic mice and littermates was checked daily over 30 days. Results are derived from 2 separate experiments for each transgenic line. The number of mice irradiated at 10.5 Gy was n = 10 for Ln 479 tg and n = 12 for wt littermates. For other irradiation doses, 10 to 15 mice were used per group (not shown). (B) Viable cell numbers of BM cells of Ln 479 transgenic (Bcl-2) and a wild-type littermate (non-tg). Bcl-2 overexpression results in higher viable cell numbers in vitro over a period of 11 days. Note that the scale on the y-axis is logarithmic. These graphs show a representative experiment out of a total of 5 experiments (7 Bcl-2 tg and 7 wt littermates ranging 10 to 24 weeks of age). Error bars indicate SEM.