GENETIC-ANALYSIS OF OXYGEN DEFENSE-MECHANISMS IN DROSOPHILA-MELANOGASTER AND IDENTIFICATION OF A NOVEL BEHAVIORAL MUTANT WITH A SHAKER PHENOTYPE

Mutants of Drosophila melanogaster that lack Cu/Zn superoxide dismutas e or urate are hypersensitive to reactive oxygen species (ROS) generat ed in vivo by the redox-cycling agent paraquat. We have subsequently e mployed paraquat as a selective agent to identify adult viable mutants potentially defective in other, perhaps unknown, components of ROS me tabolism. Paraquat screening of ethyl methanesulfonate-induced second- and third-chromosome mutations yielded 24 paraquat hypersensitive mut ants. Two mutants were identified as being new alleles of the previous ly identified doublesex (dsx) and pink (p) genes. The remainder of the mutations identified previously undescribed genes, including one seco nd chromosome paraquat hypersensitive mutant that was found to exhibit shaking legs, abdomen pulsations, and body shuddering under ether ana esthesia. This recessive mutation was mapped to the polytene chromosom e region of 48A5-48B2 and defines a new gene we named quiver (qvr). Th is mutation is similar in phenotype to the Shaker (Sh), ether-a-gogo ( eag), and Hyperkinetic (Hk) mutations, all of which affect potassium c hannel function in D. melanogaster.