B-cell development is apparently normal in recipient mice that received transplants of total bone marrow cells expressing oncogenic Kras. (A) Schematic illustration of different cell-surface markers associated with different B-cell developmental stages. (B) Flow cytometric analysis of spleen cells isolated from control mice or mice that received transplants of bone marrow cells expressing oncogenic Kras. These density plots were gated on donor-derived, live nucleated cells based on forward scatter, propidium iodide staining, and CD45.2 (donor cell marker) expression profiles. At least 10 mice with T-cell malignancy and/or JMML were examined, and representative data from one mouse are shown here. The percentages of cells in quadrants of interest are indicated.