Biosynthesis and metabolism of sulfated glycosaminoglycans during Drosophila melanogaster development

Abstract

We developed a simple methodology for labeling sulfated glycosaminoglycans (GAGs) in adult Drosophila melanogaster and studied some aspects of the biosynthesis and metabolism of these polymers during development. Adult D. melanogaster flies were fed with Na235SO4 for 72 h. During this period, 35S-sulfate was incorporated into males and females and used to synthesize 35S-sulfate-heparan sulfate (HS) and 35S-sulfate-chondroitin sulfate (CS). The incorporation of 35S-sulfate into HS was higher when compared to CS. In a pulse-chase experiment, we observed that 35S-sulfate incorporated into adult female was recovered in embryos and used for the synthesis of new 35S-sulfate-GAGs after 2 h of embryonic development. The synthesis of CS was higher than that of HS, indicating a change in the metabolism of these glycans from adult to embryonic and larval stages. Analysis of the CS in embryonic and larval tissues revealed the occurrence of nonsulfated and 4-sulfated disaccharide units in embryos, L1 and L2. In L3, in addition to these disaccharides, we also detected significant amount of 6-sulfated units that are reported here for the first time. Immunohistochemical analysis indicated that HS and CS were present in nonequivalent structures in adult and larval stages of the fly. Overall, these results indicate that 35S-sulfate-precursors are transferred from adult to embryonic and larval tissues and used to assemble different morphological structures during development. © Oxford University Press 2004; all rights reserved.