The effects of cinnamon on xanthine dehydrogenase, aldehyde oxidase, and pyridoxal oxidase activity during development in Drosophila melanogaster

Abstract

The cinnamon (cin) eye color mutant of Drosophila melanogaster was characterized to determine biochemical correlations with another mutant, maroon-like. As with maroon-like, cinnamon flies lack three enzymatic activities: xanthine dehydrogenase, aldehyde oxidase, and pyridoxal oxidase. Xanthine dehydrogenase (XDH) is subject to a maternal effect in both mutants; i.e., mutant progeny of heterozygous mothers have XDH activity, resulting in wildtype eye color. However, the maternal effect is stronger in cinnamon than in maroon-like. Whereas maternally affected cinnamon show a large increase in XDH activity during larval stages, and XDH activity is still detectable after eclosion, the magnitude of increase in XDH activity is less in maroon-like, and activity is no longer detectable in second-day pupae and all later stages. The large increase in XDH activity in maternally affected cinnamon suggests that there is de novo synthesis of enzymatically active XDH during development in the absence of the cin + gene. Cinnamon is also unique in that maternally affected flies retain isoxanthopterin (IXP), the product of XDH activity. These flies appear to be deficient in some aspect of either pteridine metabolism or excretion.