Muscle building; mechanisms of myotube guidance and attachment site selection.

The complex muscle patterns of higher organisms arise as migrating myoblasts are guided toward and connect with specific attachment sites. We review here the current understanding of myotube migration, focusing on its dynamic nature and the few molecular cues that have been identified to date. Much of this knowledge comes from studies in Drosophila, where powerful methods for in vivo imaging and genetic manipulation can be used to tackle this important but largely unsolved problem in developmental biology.