GENETIC AND TRANSGENIC APPROACHES TO DISSECTING MUSCLE DEVELOPMENT AND CONTRACTILITY USING THE DROSOPHILA MODEL SYSTEM

Both genetic and transgenic analyses of Drosophila melanogaster, the c ommon fruit fly, are providing important insights into the mechanisms of muscle cell determination and development, myofibril assembly, and muscle contraction. This model system affords tremendous advantages su ch as ease of isolating mutants defective in these processes, determin ing the identity of affected genes, and analyzing protein function by transformation with in vitro mutagenized versions of such genes. These approaches have identified a series of proteins that are critical to mesoderm and muscle determination many of which are likely to serve si milar roles in vertebrates. The effects of mutating structural protein genes upon myofibril assembly and function in Drosophila help to defi ne the differential roles of contractile protein isoforms and the impo rtance of proper protein stoichiometry for physiologic function. These studies may also provide insight into the role of structural proteins in vertebrate contractility.