The organization of any contractile system requires a series of regulated interactions between genes, structural proteins and movement to occur in a precise manner. The goal of our studies is to understand, at least in outline, some of the principles governing these interactions within the muscle cells of the nematode Caenorhabditis elegans. Our approach has been to analyze the consequences of mutations in the
unc-54 gene upon the movement of animals, the arrangement of contractile filaments within body wall muscle cells and the molecular properties of myosin.