Absolute numbers of KSL cells and expression of c-Kit on Sca1⁺lin⁻ cells. Absolute numbers of KSL cells in BM. (A) Representative cytograms of forward scatter (FSC) versus side scatter (SSC), lineage marker (top panels), and Sca-1 versus c-Kit (bottom panels) for measurements of percentages of KSL cells in Mad2^+/+ and Mad2^+/− BM cells are shown. The percentage of c-Kit⁺Sca-1⁺ cells (R4) was analyzed on gated lin⁻ cells (M1 + R1). Numbers indicate the percentage of KSL cells. (B) Data show KSL cell numbers per femur. Error bars indicate mean ± SD of measurements of 6 mice each. (C) Representative histograms of lineage marker and Sca-1 (top panels) for gating the Sca-1⁺lin⁻ cell population, and c-Kit expression (bottom panels) are shown. c-Kit expression was analyzed on gated lin⁻ cells (M1) and Sca-1⁺ cells (M2). The shaded curves show staining with anti–c-Kit antibody; the open curves show the isotype control (bottom panels). Numbers indicate the mean fluorescence intensity (MFI) of c-Kit. (D) Expression level of c-Kit on Sca-1⁺lin⁻ cells in BM. Error bars indicate mean ± SD of measurements of 4 mice each. NS indicates not significant.