Genetic Analysis of Neuronal Migration in the Nematode Caenorhabditis elegans

Abstract

During metazoan development the migrations of neurons and their growth cones play a major role in generating the final pattern and connectivity of the adult nervous system. Although many migration pathways have been described, the mechanisms regulating these cellular movements are poorly understood. In order to understand how cell migration is regulated, there are several key questions that must be addressed. How do cells decide to migrate? What defines the pathways taken by migrating cells? How do migrating cells know that they have reached their final destinations? One approach to elucidating the mechanisms controlling cell migration is to define the molecules involved by identifying mutations that perturb cell migration. The nematode Caenorhabditis elegans is particularly useful for the study of cell migration because of its anatomical simplicity. Nomarski optics can be used to observe cells as they migrate in living animals (Sulston and Horvitz, 1977; Sulston et al., 1983). Moreover, potential cell interactions involved in both cell migration (Thomas et al., 1990) and axonal guidance (Durbin, 1987; Walthall and Chalfie, 1988; Li and Chalfie, 1990; Garriga et al., 1993a) are easily tested. Our research is directed at understanding how a specific pair of motor neurons, the HSNs, migrate.