Fig. 3. The role of rpr in DNA-damage-induced death. (A,B) The absence of rpr does not suppress the ability of p53 to induce apoptosis when overexpressed in the eye. (A,C) GMR-gal4/UAS-p53 (B,D) GMR-gal4/UAS-p53; XR38/H99. (C,D) AO staining of third instar eye discs detects similar levels of ectopic apoptosis. (E-G) X-ray-induced apoptosis is suppressed in rpr nulls. Third instar larvae were irradiated with 4,000 rads and wing discs were dissected 4 hours later and stained with AO to visualize apoptotic cells. Expression of dominant-negative p53 has been shown to block X-ray-induced apoptosis under these conditions (Brodsky et al., 2000; Ollmann et al., 2000) (E) Wild-type unirradiated disc, (F) wild-type irradiated disc, (G) XR38/H99 irradiated disc.