Untersuchungen über die chemische Natur und die Bildung der Harnkonglomerate in den Malpighischen Gefäßen der Mutante rosy von Drosophila melanogaster

Abstract

During the different periods of development the mutant rosy of Drosophila melanogaster has been shown to contain yellowish globules in the Malpighian tubes in different number and position (figs. 1, 2). These globules are excreted by the hind-gut. The Chromatographic analysis indicates that the globules of the larvae and the pupae consist of two compounds : 2-amino-4-hydroxypteridine and xanthine. A third compound, the hypoxanthine, is added to the excretory granules in the lumen of the Malpighian tubes of the adults. The larvae of the wild type accumulate all the purines in the fat-body. Besides the accumulation in the fat-body the mutant in contrary excretes xanthine into the Malpighian tubes already during the larval stage. The occurrence of the three substances: 2-amino-4-hydroxypteridine, xanthine and hypoxanthine, which generally are not found in the Malpighian tubes of wild type, and the concentration of the urine by reabsorption of water in the proximal parts of the tubes seem to cause the formation of the solid conglomerates. The formation of uric acid in Drosophila is discussed.