Fig. 3. Pc mutant neuroblasts undergo programmed cell death. (A) Time course analysis of programmed cell death. Clones were induced at 24 hours, 48 hours and 72 hours before examination in late third-instar larvae (top). The percentage of mutant Pc clones containing a neuroblast is plotted for each of the three temporal induction programs (bottom, light gray bars). The number of clones examined is indicated in parentheses. The percentage of clones containing anti-caspase immunoreactive neuroblasts is also plotted (dark gray bar). Caspase activation and disappearance of the progenitor marker was observed predominantly 48 hours after clonal induction. (B-B") Confocal image of a CD8::GFP-labeled Pc mutant clone stained for the progenitor marker Mira (blue) showing a dying neuroblast (arrowhead). Programmed cell death is specifically detected in the neuroblast by anti-activated Caspase-3 antibody (magenta).