Development, structure, and maintenance of C. elegans body wall muscle

In C. elegans, mutants that are defective in muscle function and/or structure are easy to detect and analyze since: 1) body wall muscle is essential for locomotion, and 2) muscle structure can be assessed by multiple methods including polarized light, electron microscopy (EM), Green Fluorescent Protein (GFP) tagged proteins, and immunofluorescence microscopy. The overall structure of the sarcomere, the fundamental unit of contraction, is conserved from C. elegans to man, and the molecules involved in sarcomere assembly, maintenance, and regulation of muscle contraction are also largely conserved. This review reports the latest findings on the following topics: the transcriptional network that regulates muscle differentiation, identification/function/dynamics of muscle attachment site proteins, regulation of the assembly and maintenance of the sarcomere by chaperones and proteases, the role of muscle-specific giant protein kinases in sarcomere assembly, and the regulation of contractile activity, and new insights into the functions of the dystrophin glycoprotein complex.