mummy encodes an UDP-N-acetylglucosamine-dipohosphorylase and is required during Drosophila dorsal closure and nervous system development

Abstract Throughout development cell–cell interactions are of pivotal importance. Cells bind to each other or share information via secreted signaling molecules. To a large degree, these processes are modulated by post-translational modifications of membrane proteins. Glycan-chains are frequently added to membrane proteins and assist their exact function at the cell surface. In addition, the glycosylation pathway is required to generate GPI-linkage in the endoplasmatic reticulum. Here, we describe the analysis of the cabrio / mummy gene, which encodes an UDP- N -acetylglucosamine diphosphorylase. This is a well-conserved and central enzyme in the glycosylation pathway. As expected from this central role in glycosylation, cabrio / mummy mutants show many phenotypic traits ranging from CNS fasciculation defects to defects in dorsal closure and eye development. These phenotypes correlate well with specific glycosylation and GPI-anchorage defects in mummy mutants.