This application has 3 major aims, all of which arise from our ongoing research aimed at understanding membrane repair in general, and limb-girdle type IIB muscular dystrophy and Myoshi myopathy (LGMD2B/MM) in particular. 1. Test the role of annexins, and other protein candidates, in membrane repair by skeletal muscle cells and the effect of dysferlinopathy on annexin-related and other repair pathways. 2. Develop techniques for quantitatively monitoring membrane repair that can be used in a high-throughput assay capable of detecting small chemicals having the potential for promoting membrane repair by dysferlin null muscle fibers. 3. Continue to act as a community resource, providing advice and help in developing membrane repair assays, and conducting laser-based assays of membrane repair.