Author contributions: Experiments were designed by FM and BM and carried out by FM. Manuscript was prepared by FM and BM.
Drosophila multiplexin (Dmp) modulates motor axon pathfinding accuracy
Article first published online: 13 MAY 2009
© 2009 The Authors. Journal compilation © 2009 Japanese Society of Developmental Biologists
Development, Growth & Differentiation
Volume 51, Issue 5, pages 483–498, June 2009
How to Cite
Meyer, F. and Moussian, B. (2009), Drosophila multiplexin (Dmp) modulates motor axon pathfinding accuracy. Development, Growth & Differentiation, 51: 483–498. doi: 10.1111/j.1440-169X.2009.01111.x
- Issue published online: 1 JUN 2009
- Article first published online: 13 MAY 2009
- Received 22 September 2008; revised 20 March 2009; accepted 20 March 2009
- collagen XVIII and XV;
- extracellular matrix;
- motoaxon guidance
Multiplexins are multidomain collagens typically composed of an N-terminal thrombospondin-related domain, an interrupted triple helix and a C-terminal endostatin domain. They feature a clear regulatory function in the development of different tissues, which is chiefly conveyed by the endostatin domain. This domain can be found in proteolytically released monomeric and trimeric versions, and their diverse and opposed effects on the migratory behavior of epithelial and endothelial cell types have been demonstrated in cell culture experiments. The only Drosophila multiplexin displays specific features of both vertebrate multiplexins, collagens XV and XVIII. We characterized the Drosophila multiplexin (dmp) gene and found that three main isoforms are expressed from it, one of which is the monomeric endostatin version. Generation of dmp deletion alleles revealed that Dmp plays a role in motor axon pathfinding, as the mutants exhibit ventral bypass defects of the intersegmental nerve b (ISNb) similar to other motor axon guidance mutants. Transgenic overexpression of monomeric endostatin as well as of full-length Dmp, but not trimeric endostatin, were able to rescue these defects. In contrast, trimeric endostatin increased axon pathfinding accuracy in wild type background. We conclude that Dmp plays a modulating role in motor axon pathfinding and may be part of a buffering system that functions to avoid innervation errors.