Peroxisomes in the head of Drosophila melanogaster.

Peroxisomes were localized in the head of wild-type and mutant strains of Drosophila melanogaster by use of a cytochemical method for the demonstration of D-amino acid oxidase activity. With similar techniques we had found previously that vertebrate photoreceptors have few, if any, bodies with cytochemically demonstrable oxidase activity, but that the pigment epithelial cells adjacent to the photoreceptors have a substantial population of such bodies. Peroxisomes in Drosophila were very abundant in the fat body. Probable peroxisomes were also present in the peripheral retina of the eye, including in retinular (retinula) and pigment cells, but there were very few of them. Thus, our results suggest that the fat body, which lies adjacent to the eye, is the principal site of peroxisomal function in the head. Peroxisome functions in the Drosophila head may include participation in the genesis of eye pigments.