Axon Patterning Requires D N-cadherin, a Novel Neuronal Adhesion Receptor, in the Drosophila Embryonic CNS

AbstractWe identified D N-cadherin, a novel Drosophila cadherin that is expressed in axons and in the mesoderm. Although D N-cadherin has diverged from vertebrate classic cadherins in terms of its extracellular structure, it still can form a complex with catenins and induce cell aggregation, as do the vertebrate molecules. Loss-of-function mutations of the gene resulted in either embryonic lethality or uncoordinated locomotion of adults. In the central nervous system of null mutant embryos, subsets of ipsilateral axons displayed a variety of aberrant trajectories including failure of position shifts, defective bundling, and errors in directional migration of growth cones. These results suggest that processes of axon patterning critically depend on D N-cadherin-mediated axon–axon interactions