Figure 1.

Crossing schemes used to generate 0 and 50% cSOD flies (A–C) and 30 and 80% cSOD flies (D–F). In all crosses adults were placed on fresh cornmeal-corn syrup-yeast-agar media and allowed to mate and lay eggs for 1 wk, moved to fresh media for 1 wk, then discarded. Crosses (A, D) and (B, E) were set up using two male and two virgin female flies. Single males were crossed to two virgin females in cross (C, F) as male progeny from cross (B, E) expressing the curly wing phenotype could have possessed one of two genotypes, only one of which was desired for cross (C, F). Use of single males prevented mixing males with different genotypes and allowed crosses that had been set up with the incorrect genotype to be discarded. Cross (C) generated (i) w⁺;T0/DGRPⁱ;csodⁿ¹⁰⁸,red/csodⁿ¹⁰⁸,red (0% wild-type cSOD activity) and (ii) w⁺; T0/DGRPi;csodⁿ¹⁰⁸,red/VT83 (50% wild-type cSOD activity). Cross (C) also produces w⁺;T0/CyO;csodⁿ¹⁰⁸,red/csodⁿ¹⁰⁸,red, w⁺;T0/CyO; csodⁿ¹⁰⁸,red/VT83, w⁺;T0/CyO; csodⁿ¹⁰⁸,red/TM3, ser, w⁺;T0/CyO; VT83/TM3, ser, w⁺;T0/DGRPⁱ; csodⁿ¹⁰⁸,red/TM3, ser, and w⁺;T0/DGRPⁱ; VT83/TM3, ser genotypes. Cross (F) generated (i) w⁺;T5/DGRPi;csodⁿ¹⁰⁸,red/csodⁿ¹⁰⁸,red (30% wild-type cSOD activity) and (ii) w⁺; T5/DGRPi;csodⁿ¹⁰⁸,red/VT83 (80% wild-type cSOD activity). Cross (F) also produces w⁺;T5/CyO;csodⁿ¹⁰⁸,red/csodⁿ¹⁰⁸,red, and w⁺;T5/CyO; csodⁿ¹⁰⁸,red/VT83 progeny. Across genotypes, female flies were heterozygous at the X chromosome for w⁺/w¹¹¹⁸, while males were hemizygous for the w⁺ allele. The four genotypes carrying the TM3, Sb 3rd chromosome balancer, produced by (C), are distinguished by a stubble bristles phenotype and have been removed from analysis as the four genotypes encompass two phenotypes that are visually indistinguishable and possess different levels of cSOD activity. The genotypes carrying the CyO chromosome, produced in (C) and (F), have been excluded from the analyses as preliminary results suggested the balancer chromosome was falsely driving genetic background differences. cSOD, cytosolic copper/zinc superoxide dismutase.