Alteration of PI3K signaling does not affect B cell progenitor proliferation. (A) B cell progenitors from WT and Bim^−/− bone marrow were cultured in the presence of IL-7 with or without LY294002 for 24 h. Cells were then fixed and analyzed for DNA content and the percentage of cells in G₁ versus SG₂M phase of cell cycle are provided. Data are representative of three independent experiments. (B) B cell progenitors from Bim^−/− bone marrow were cultured in the presence of IL-7 with or without LY294002 for 24 h. TCLs were prepared in NP-40 lysis buffer, resolved by SDS-PAGE, and membranes probed for cyclin D3 and Actin. Relative molecular mass (kD) is as indicated. Data are representative of three independent experiments. (C) Flow cytometry for expression of B220, CD43, and IgM by bone marrow cells from p85α^+/− and p85α^−/− mice. Numbers in contour plots indicate the percentage of cells in each gate. Representative data, n = 8. (D) Relative number of cells in each population determined using total number of bone marrow cells after red blood cell lysis and percentages from flow cytometry. Each point represents a single mouse and bars represent the mean for each population. (E) The corresponding populations from C were analyzed for DNA content. Numbers in histogram plots indicate the percentage of cells in G₁ and SG₂M phases of cell cycle. (F) Summary of the percentage of cells in SG₂M from each population. Each point represents a single mouse and bars represent the mean for each population. (G and H) bPTEN^+/+ and bPTEN^−/− bone marrow was analyzed as in C and D (G), and the percentage of cells in SG₂M from each population was summarized (H), n = 4. Each point represents a single mouse and bars represent the mean for each population. *, P < 0.05.