Neurons have structurally and functionally distinct processes, the axon and the dendrite. The segregation of proteins into these compartments is essential for the normal functioning of the neuron. Despite the fundamental importance of this process, little is known about how neurons become polarized. This proposal seeks to investigate this process using C. elegans genetics. Both molecular and phenotype-driven analyses will be undertaken. For the former, candidate genes will be tested for their role in neuronal polarity. For the latter, a genetic screen will be undertaken to identify novel components of this process. In addition to providing insight into neuronal polarity in particular, these experiments could lead to a greater understanding of how cells become polarized in general. Thus this work could have implications far beyond the scope of neurobiology, into areas such as cancer research and immunology.