Fig. 8. Rolling pebbles signaling between precursor cells and FCMs is necessary to stabilize cell contacts and to initiate progression in fusion such as prefusion complex formation. In wild-type myoblasts fusion proceeds after adhesion of FCMs to precursor cells by forming the prefusion complex of paired vesicles followed by plaque formation of the opposing membranes and subsequent membrane breakdown. In rols mutants the initial adhesion of precursor cells with FCMs is observed but cells scatter instead of proceeding to prefusion complex formation, showing its first function before sns and blow but after the initial Duf function.
