FIG. 2.

Puma deficiency accelerates Myc-induced lymphomagenesis. (A) Tumor-free survival of Eμ-Myc; Puma^−/− (n = 17, blue), Eμ-Myc; Puma^+/− (n = 24, purple), and Eμ-Myc; Puma^+/+ (n = 15, red) animals. (B) Early infiltration of premalignant B cells in the spleens and bone marrow of Eμ-Myc; Puma^−/− mice. Histology of spleen tissue (upper) and bone marrow (lower) from Puma^+/+, Puma^−/−, Eμ-Myc; Puma^+/+, and Eμ-Myc; Puma^−/− mice. Specimens were stained with the B-cell marker Pax-5 (data shown are representative of three independent experiments). (C) Puma deficiency protects against Eμ-Myc transgenic B-cell apoptosis without altering Myc-induced cell proliferation. Splenic B220⁺/IgM⁺ B cells from 7-week-old mice were analyzed by FACS for cell proliferation (left) and apoptosis (right) (n = 3 individual animals of each genotype).