The key genes and processes involved in muscle formation are conserved between vertebrates and Drosophila .
Founders possess all of the information needed to specify the identity of the individual muscles.
We have identified a gene, called kirre , that is required for the two subclasses of muscle precursors to recognize and fuse to one another. The kirre protein is expressed specifically on the surface of founders where it interacts with unknown receptors on the surface of fusion competent cells to induce them to migrate toward the founders. We are now in position to answer two key questions in muscle formation. To address these questions we are using modern molecular-genetic techniques to identify and characterize the proteins that interact with kirre in the fusion process. Any number of different types of proteins could be involved, e.g., cell surface proteins, components of intracellular signaling pathways, regulators of the cytoskeleton, etc.