MUTATIONS IN THE DROSOPHILA NEUROGLIAN CELL-ADHESION MOLECULE AFFECT MOTOR-NEURON PATHFINDING AND PERIPHERAL NERVOUS-SYSTEM PATTERNING

We have identified and characterized three embryonic lethal mutations that alter or abolish expression of Drosophila Neuroglian and have use d these mutations to analyze Neuroglian function during development, N euroglian is a member of the immunoglobulin superfamily, It is express ed by a variety of cell types during embryonic development, including expression on motoneurons and the muscle cells that they innervate, Ex amination of the nervous systems of neuroglian mutant embryos reveals that motoneurons have altered pathfinding trajectories. Additionally, the sensory cell bodies of the peripheral nervous system display alter ed morphology and patterning. Using a temperature-sensitive mutation, the phenocritical period for Neuroglian function was determined to occ ur during late embryogenesis, an interval which coincides with the per iod during which neuromuscular connections and the peripheral nervous system pattern are established, (C) 1997 John Wiley & Sons, Inc.