Overlapping roles of Bim and Bmf in the control of pre-B-cell survival. (A) Pre-B cells (B220⁺CD43⁻IgM⁻) were isolated from the bone marrow of 7- to 9-week-old mice of the indicated genotypes and placed in culture (left) without additional treatment or in the presence of 10 ng/mL recombinant IL-7. (Right) Relative survival advantages induced by IL-7 were assessed over time. (B) B220⁺IgM⁻ pro/pre-B cells were sorted from the bone marrow of 7- to 9-week-old mice of the indicated genotypes and cultured for 96 hours in the presence or absence of IL-7. sIgM expression was monitored by flow cytometric analysis. Representative dot plots from 1 of 3 independent experiments are shown. (C) Fluorescence-activated cell sorter-sorted pre-B cells from the bone marrow of 7- to 9-week-old mice of the indicated genotypes were treated in culture with the HDAC inhibitor SAHA or the glucocorticoid dexamethasone, and cell survival was assessed over time by flow cytometric analysis. Data are presented as means ± SEM of ≥3 independent experiments and 3 to 6 animals per genotype. *Significant differences by ANOVA (P < .05) at individual time points between WT and Bmf^−/− derived cells; ^&between WT and Bim^−/−, ^βbetween Bim^−/− and Bmf^−/−, ^#between WT and DKO, and ^§between Bim^−/− and DKO cells. Due to differences in spontaneous cell death in culture, specific drug-induced killing was calculated using the formula (induced apoptosis − spontaneous cell death)/(100 − spontaneous cell death) (%).