Singling out Drosophila tendon cells - a dialogue between two distinct cell types

The precise match between somatic muscles and their epidermal attachment ce lls is achieved through a continuous dialogue between these two cell types. Whereas tendon cells direct myotube migration and final patterning, the mu scles are essential for the maintenance of the fate of tendon cells. The Dr osophila neuregulin-like ligand, Vein, and its receptor, the epidermal grow th factor receptor (Egfr), are critical components in the inductive signali ng process that takes place between muscles and tendon cells. Additional ge ne products that relay the Vein-Egfr effect in Drosophila are conserved in the vertebrate neuregulin-mediated cascade. This review describes genetic a nd molecular aspects of the muscle-tendon inductive processes in Drosophila , and compares them with the relevant mechanisms in the vertebrate embryo.