THE EFFECT OF SUPEROXIDE-DISMUTASE ALLELES ON AGING IN DROSOPHILA

The effects of superoxide dismutase on aging were tested using two dif fert experimental approaches. In the first, replicated populations wit h Postponed aging were compared with their controls for frequencies of electrophoretic alleles at the SOD locus. Populations with postponed aging had consistently greater frequencies of the allele coding for mo re active SOD protein. This allele was not part of a segregating inver sion polymorphism. The second experimental approach was the extraction of SOD alleles from different natural populations followed by the con struction of different SOD genotypes on hybrid genetic backgrounds. Th is procedure did not uncover any statistical effect of SOD genotype on longevity or fecundity. There were large effects on longevity and fec undity due to the family from which a particular SOD genotype was deri ved. To detect the effects of SOD genotypes on longevity with high pro bability would require a ten-fold increase in the number of families u sed.