The development of the epidermis of the nematode worm Caenorhabditis elegan
s illustrates many common processes of epithelial morphogenesis. In the wor
m, these morphogenetic movements have been described with single-cell resol
ution, and the roles of individual cells have been probed in laser killing
experiments. Genetic dissection is yielding insights into the molecular mec
hanisms of these complex morphogenetic processes.