Fig 4. Interaction of corp and p53.

(A) The p53 ^5A-1-4 mutation is epistatic to corp in the BARTL assay. The corp ^95B mutation produces headless flies in the BARTL assay (reproduced from Fig 2), while p53 ^5A-1-4 has the opposite effect, producing flies with wildtype eyes. The double mutant is indistinguishable from the p53 ^5A-1-4 single mutant. N represents the number of eyes or headless pharates scored. Genotypes used were y w corp ^95B /H1; eyGal4 UAS-FLP, or y w/H1; eyGal4 UAS-FLP/+; p53 ^5A-1-4, or y w corp ^95B /H1; eyGal4 UAS-FLP/+; p53 ^5A-1-4. (B-C) The p53 ^5A-1-4 mutation suppresses elevated apoptosis observed in corp ^95B mutants. TUNEL staining of wing discs following irradiation shows that apoptosis is highly reduced in p53 ^5A-1-4 mutants, compared to intense cell death in corp ^95B mutants (reproduced from Fig 3A). corp ^95B ; p53 ^5A-1-4 double mutants also show reduced cell death, similar to p53 ^5A-1-4 single mutants. Wing discs were TUNEL stained 3 hours after 4000 rads of irradiation. (C) Quantitation. Intensity of TUNEL staining is expressed as integrated density per unit area of the wing disc. (D) Overexpression of corp ⁺ suppresses the apoptotic phenotype caused by overexpression of p53 ⁺. Eye sizes were measured from flies that overexpressed p53 ⁺, and that also overexpressed corp ⁺ or were corp ^95B mutants. The Y-axis indicates eye size normalized to wildtype eyes. (F;a-c, G) Overexpression of corp ⁺ inhibits cell death caused by overexpression of p53 ⁺. GMR drives p53 ⁺ expression to produce cell death posterior to the morphogenetic furrow, assayed here by TUNEL staining, The corp mutant greatly enhances TUNEL staining while corp ⁺ overexpression reduces TUNEL staining. Genotypes are as indicated. All images were taken with a 40X objective. (G) TUNEL staining is quantified as InD/area of eye disc posterior to morphogenetic furrow. (E) corp ⁺ overexpression suppresses the cell-death phenotypes mediated by hid ⁺ or reaper ⁺ overexpression. GMR-Gal4 was used to drive corp ⁺, hid ⁺ and reaper ⁺ overexpression. The Y-axis represents eye size as in D. (F;d-g, H) corp ⁺ overexpression inhibits apoptosis caused by hid ⁺ or reaper ⁺ overexpression. GMR-Gal4 was used to drive corp ⁺, hid ⁺ and reaper ⁺ overexpression, to produce cell death posterior to the morphogenetic furrow. All images were taken with a 40X objective. (H) Staining is quantified as InD/area, as described above. Red arrowheads in part F indicate approximate position of the morphogenetic furrow in each image. Posterior is to the right. N, the number of eyes or imaginal discs measured for quantification.