EFFECTS OF CINNAMON ON XANTHINE DEHYDROGENASE, ALDEHYDE OXIDASE, AND PYRIDOXAL OXIDASE ACTIVITY DURING DEVELOPMENT IN DROSOPHILA-MELANOGASTER

The cinnamon (cin) eye color mutant of D. melanogaster was characterized to determine biochemical correlations with another mutant, maroon-like (mal). As with mal, cin flies lacked 3 enzymatic activities:xanthine dehydrogenase, aldehyde oxidase and pyridoxal oxidase. Xanthine dehydrogenase (XDH) was subject to a maternal effect in both mutants; i.e., mutant progeny of heterozygous mothers had XDH activity, resulting in wild-type eye color. The maternal effect was stronger in cin than in mal. Whereas maternally affected cin showed a large increase in XDH activity during larval stages, and XDH activity was still detectable after eclosion, the magnitude of increase in XDH activity was less in marl, and activity was no longer detectable in 2nd-day pupae and all later stages. The large increase in XDH activity in maternally affected cin suggested that there was de novo synthesis of enzymatically active XDH during development in the absence of the cin+ gene. Cin was unique in that maternally affected flies retained isoxanthopterin (IXP), the product of XDH activity. These flies appeared deficient in some aspect of either pteridine metabolism or excretion.