Resistance to killing by H₂O₂ feeding. Flies of the indicated genotypes were assayed for survival while being fed 5% H₂O₂. Data are presented as percent survival. A total of 140 to 200 flies were analyzed for each survival curve. Results of nonparametric statistical analyses are presented below each graph.

Correlation of SOD overexpression with life span. The amount of Cu/ZnSOD overexpression (HP minus Co), in arbitrary Cu/ZnSOD enzyme activity units, was plotted against the change in life span (HP minus Co), in days, in scatter plots. (A) D genetic background, data from Fig. 3C and D and Table 3; r = 0.87, P = 0.0005. (B) T genetic background, data from Fig. 3F and G and Table 3; r = 0.70, P = 0.047.

Catalase enzyme activity assay. Catalase enzyme activity was quantitated in extracts of whole flies of the indicated genotypes. (A) Control lines. (B) Lines transgenic for FLP¹ and the indicated catalase overexpression construct insertions. (C) Repeat of experiment in panel B. (D) Lines transgenic for FLP¹ plus the indicated catalase insertion plus the indicated SOD insertion. (E) Repeat of experiment in panel D. The data are the mean and standard deviation of triplicate assays. Statistically significant differences (P < 0.05) between HP and Co were determined with two-sided t tests and are indicated by an asterisk.

FLP-OUT system. (A) hsp70:FLP construct in the FLP¹ transgenic line. (B) lacZ-catalase-Cu/ZnSOD expression constructs before recombination. (C) Expression constructs after FLP/FRT-mediated recombination. In the catalase and Cu/ZnSOD expression constructs, the transcriptional stop sequence is the 3′ end and polyadenylation signal sequence of the hsp70 gene, while in the lacZ expression construct the stop sequence is the Draf gene (53). (D) β-gal enzyme levels were assayed in extracts of adult Drosophila of the indicated genotypes. The data are the mean and standard deviation of triplicate assays. Statistically significant differences (P < 0.05) between HP and Co were determined with two-sided t tests and are indicated by an asterisk.

SOD enzyme activity assay. Total SOD enzyme activity was quantitated in extracts of whole flies of the indicated genotypes. The data show the percentage to which extract inhibits the oxidation of quercetin in the presence of TEMED and are the mean and standard deviation of triplicate assays. Statistically significant differences (P < 0.05) between HP and Co were determined with two-sided t tests and are indicated by an asterisk. (A) Control lines, including both the D and T backgrounds, as indicated. (B) Flies transgenic for FLP¹ and the indicated SOD construct insertions, D background, assay 1. The FLP¹;SOD^2B2 sample was lost, and therefore the experiment was performed two more times. (C) Flies transgenic for FLP¹ and the indicated SOD construct insertions, D background, assay 2. (D) Flies transgenic for FLP¹ and the indicated SOD construct insertions, D background, assay 3. (E) Flies transgenic for FLP¹ and the indicated SOD construct insertions, T background, assay 1. (F) Flies transgenic for FLP¹ and the indicated SOD construct insertions, T background, assay 2. (G) Flies transgenic for FLP¹ plus the indicated catalase construct insertion plus the indicated SOD construct insertion, in D or T backgrounds, as indicated, assay 1. (H) Flies transgenic for FLP¹ plus the indicated catalase construct insertion plus the indicated SOD construct insertion, in D or T backgrounds, as indicated, assay 2. The induction of the double-SOD line, SOD^2A;SOD^3A1 is significant or marginally significant if the replicate experiments are combined: for the D background (B⁵ + C⁵ + D⁵), P = 0.05; for the T background (E⁵ + F⁵), P = 0.10. Similarly, if replicate experiments are combined for the CAT plus SOD lines, the induction of SOD is significant or marginally significant for the following genotypes: CAT^2A2;SOD^3A1 (G¹ + H¹) P = 0.05, CAT^2B2;SOD^3A1 (G² + H²) P = 0.05, CAT^2A2;SOD^3B1 (G³ + H³) P = 0.10.