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

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.