Impaired B cell development in the absence of ASCIZ is rescued by deletion of Bim. (A and B) Relative spleen weights (A) and total numbers of splenic B220⁺IgM⁺ B cells (B) in Mb1/Mb1-Cre Asciz^fl/fl deleters (n = 5), Bim KO (n = 6), double mutants (n = 11), and controls (n = 6). All controls and all Bim KO mice are Mb1/Mb1-Cre Asciz^+/+. Data were obtained in five independent experiments. (C) Bone marrow phenotyping (left) and total cell numbers (right) for B220^lowIgM⁺-gated immature B cells in one hind limb of Mb1/Mb1-Cre Asciz^fl/fl deleters (n = 5), Bim KO mice (n = 6), double mutants (n = 11), and controls (n = 6). The animals are the same as in A. (D) Pre-B cell numbers (B220⁺IgM⁻CD43⁻CD19⁺) in Mb1/Mb1-Cre Asciz^fl/fl deleters (n = 3), Bim KO mice (n = 4), double mutants (n = 9), and controls (n = 4). All controls and all Bim KO mice are Mb1/Mb1-Cre Asciz^+/+. The data were obtained in three independent experiments. (A–D) Each symbol represents one mouse. Error bars represent mean ± SEM.