Increased turnover of B cells from Vav-deficient mice. (A) Sorted mature B cells (CD93^-, CD23⁺, IgM⁺) from wild-type and Vav-deficient mice were incubated in culture medium for the indicated time points. Viability was assessed by propidium iodide (PI) exclusion. □ indicates wild type; ▪, Vav-deficient. (B) Wild-type or Vav-deficient mice were continuously administered BrdU and analyzed using antibodies for CD93, IgM, CD23, and BrdU at the indicated time points. CD93⁺ and CD93^- cells were subdivided using IgM and CD23 levels, as shown in Figure 1A-B, and the percentage of BrdU-positive cells was calculated within each gate. Each data point represents the mean ± SD of measurements from 3 mice. (▪) Wild-type mice. (▾) Vav-deficient mice. Statistical analysis for T2 cells was performed using the Student t test; ^*P < .001. Two-way ANOVA of T3 subset produced the following results: wild-type mean, 38.3; Vav^-/- mean, 57.1; SE, 1.31; P < .001. For mature FO B cells: wild-type mean, 4.7; Vav^-/- mean, 10.5; SE, 1.34; P < .01. Details of the application of ANOVA are described in “Materials and methods.”