Intracellular localization of kynurenine in the fatbody of Drosophila.

Light blue fluorescent globules accumulate in the cells of the anterior region of the fatbody of Drosophila larvae near the time of pupation. This fluorescent material appears in the Ore-R wild type strain as well as mutant strains in which the synthesis of both the red and brown eye pigments is affected. The vermilion mutant, which is characterized by the absence of the brown pigment component in the eye, was the only strain among those examined which did not develop the light blue fluorescent globules. Utilizing chromatographic techniques together with the information gained by examination of the mutant strains, the fluorescent material has been identified as kynurenine. Of particular interest is the manner of appearance of the fluorescent material in the vicinity of the nuclear membrane of the fat cells.