Quantitative differences in xanthine dehydrogenase activity in wild-type strains ofDrosophila melanogaster

Summary and conclusions A series of 98 wild type strains ofD. melanogaster were surveyed for their xanthine dehydrogenase activities. It was found that all strains had enzyme activity and that extensive differences existed between strains. Subsequent analyses estimated that between 83% and 93% of the variation was due to genetic differences. The subsequent demonstration of the presence of a recessive gene on the third chromosome (lxd) resolved some of the variation attributed to genetic differences. The relative smoothness of the distribution of enzyme activites of the individual flies indicated that a major portion of the differences in enzyme activity is probably due to polygenic factors with small individual effects.With 1 Figure in the TextThis work was supported by a grant (GM-08202) from the National Institutes of Health awarded toDr. E. Glassman.