Overexpression of Bcl-2 partially rescues B-cell development of Vav-deficient cells. Recipient mice were reconstituted with bone marrow cells from Vav-deficient mice with or without expressing transgenic Bcl-2 (7 and 8 mice, respectively). Wild-type mice carrying or not carrying the Bcl-2 transgene were used as controls (5 mice each). Spleen cells were analyzed at 6 weeks after reconstitution. (A) B cells of the indicated genotype were stained and analyzed as described in Figure 1. (B) B cells identified as B220⁺ were further analyzed by staining using antibodies against CD23 and CD21. Numbers shown represent the percentages of B cells falling within the regions illustrated.