URIC-ACID IN ANOPHELES MOSQUITOS (DIPTERA, CULICIDAE) - EFFECTS OF COLLARLESS, STRIPE, AND WHITE MUTATIONS

Anopheles mosquito larvae and pupae often have a layer of white pigmen t visible beneath the transparent cuticle on the dorsum of the abdomen and thorax. This pigment occurs in granules that are highly concentra ted in ameboid-shaped cells of the parietal fat body. Mutations that a ffect the pattern or abundance, or both, of this pigment in A. albiman us Wiedemann and A, gambiae Giles are characterized by differences in the abundance of uric acid, whose levels range from 1.86 to 3.13 mu g per larvae in individuals of 4 phenotypes having white pigmentation. U ric acid concentrations are higher in A. albimanus stripe(+) individua ls which also have the most prominent white pigment. Two other mutants , A. gambiae collarless and A. albimanus white eye, contain no detecta ble uric acid nor any white pigment. None of the mutants examined has reduced xanthine dehydrogenase activity nor altered XDH electrophoreti c mobility. We suggest that the prominent white pigment is precipitate d uric acid contained within specialized fat-body cells similar to uro cytes. Mie discuss the genetic basis of mutants affecting uric acid de position, and the pleiotropic effects of the rye-color mutations such as white.