Reduced Bcl expression in Stat5-deficient BMMCs. (A) Wild-type or Stat5-deficient BMMCs were cultured in IL-3 (0.02 ng/mL) or SCF (10 ng/mL) for 24 hours. Control cultures were maintained in IL-3 (5 ng/mL) + SCF (50 ng/mL). Total RNA was subjected to RPA analysis. For each culture, the ratio of Bcl-x(L) or Bcl-2 expression to the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and L32 loading controls was determined. These ratios were then used to determine relative changes in Bcl-x(L) or Bcl-2 expression in cultures containing IL-3 or SCF alone to the same cells cultured in IL-3 + SCF. This percentage of Bcl-x(L) and Bcl-2 expression relative to IL-3 + SCF is plotted in the bar graph next to the autoradiogram. These data are from 1 of 3 experiments that gave similar results. (B) Wild-type and Stat5-deficient BMMCs were cultured as in panel A for 36 hours, and total cell lysates were subjected to Western blot analysis for the indicated Bcl proteins. The same filter was stripped and reprobed for actin to show protein loading.