Neuronal dendrites and axons have distinct functions and morphologies, and,to wire up the nervous system correctly, their development must be coordinated. On ,Grueber and colleagues provide an analysis of axon projections from different types of dendritic aborization (da) sensory neurons in Drosophila and identify some new genes involved in axon and dendrite development. These neurons, which lie just below the transparent body wall in Drosophila, form four classes based on their dendritic morphology. The researchers use mosaic cell-labelling techniques to analyze da neuron axon projections in embryonic and larval stages. They report that the axons in da neurons in different dendritic classes have distinct morphologies and organize into different layers of the CNS, a novel finding that suggests that each class has a distinct function. They also use forward genetic screening to identify loci that are involved in sensory dendrite and/or axon patterning. This new information provides a firm foundation for understanding the similarities and differences in the morphogenesis of axons and dendrites.
