Fig. 7. Hypothesis for the function of Kette during the second myoblast fusion step compared with the known function of Kette during axonal outgrowth. We propose that the function of Dock/NCK, which mediates Kette function during neurogenesis (Bogdan and Klämbt, 2003), is taken over by Crk, which has also been shown to interact with Blow and Mbc, and to be involved in Rac1 activation and the formation of lamellipodia (see text for details).