XANTHINE DEHYDROGENASE: DIFFERENCES IN ACTIVITY AMONG DROSOPHILA STRAINS.

In Drosophila melanogaster, mutants at two loci are known to lack detectable amounts of xanthine dehydrogenase activity. These are the maroon-like eye-color locus on the X chromosome and the rosy-eye-color locus on the third chromosome (52+/-). A survey was made of the xanthine dehydrogenase content of 98 wild-type strains of D. melanogaster. One strain with 25 percent of the xanthine dehydrogenase activity found in normal flies is described. Strains with high xanthine dehydrogenase activity have also been obtained by selection.