Fig. 3. p53-dependent activation of the JNK signaling pathway is required for -radiation-induced apoptosis. Third-instar wing discs. (A) DIC. en-Gal4 (schematically overlaid in red) is expressed in the posterior compartment. (B-E) Wing discs oriented as in A. JNK^REP (red), actin (blue). (B) Untreated puc^A251.1/+. (C-E) Four hours after -radiation (4000 rads here and below). (C) puc^A251.1/+, (D) en-Gal4/UAS-myc-Puc; puc^A251.1/+ and (E) en-Gal4/UAS-myc-Puc^DEAD; puc^A251.1/+. (F-H) TUNEL (green), Myc-Puc (red) and DNA (blue). Untreated (F) or -irradiated (G,H) discs expressing Myc-Puc (G) or Myc-Puc^DEAD (H) in the posterior compartment. (G',H') TUNEL alone. (I,J) TUNEL (green), JNK^REP (red) and DNA (blue). (I) -irradiated puc^A251.1 p53^[5A-1-4]/+ p53^[5A-1-4] disc. (J) Untreated en-Gal4/UAS-p53^GUS2.1; puc^A251.1/+ disc. (J',J'') Posterior compartment of J: JNK^REP (J') and TUNEL (J''). (K) en-Gal4 UAS-myc-Puc /UAS-p53^GUS2.1 mutant. TUNEL (green, K''), Myc-Puc (red, K') and DNA (blue).