Mutations in β-spectrin disrupt axon outgrowth and sarcomere structure

B-Spectrin is a major component of the membrane skeleton, a structure found at the plasma membrane of most animal cells. B-Spectrin and the membrane skeleton have been proposed to stabilize cell membranes, generate cell polarity, or localize specific membrane proteins. We demonstrate that the Caenorhabditis elegans homologue of B-spectrin is encoded by the unc-70 gene. unc-70 null mutants develop slowly, and the adults are paralyzed and dumpy.