Cell death 6 days after culture with SCF plus GM-CSF. (A) c-Kit⁺lin⁻ bone marrow cells (2 × 10⁵) from wild-type and Mad2^+/− mice were cultured in a 12-well tissue-culture plate in the presence of SCF (50 ng/mL) plus GM-CSF (10 ng/mL) for 6 days. Representative histograms of Mad2^+/+ and Mad2^+/− BM cells are shown. Numbers in histograms correspond to the percentage of annexin V⁺ cells. (B) Data represent the average of triplicate samples, and error bars represent 1 SD from the mean for triplicate wells. Result shown is representative of 2 independent experiments. *P < .01 (+/− vs +/+).