Dvl2 and Rac1 are required for Wnt7a-induced cell migration. (A) Fzd7-tdTomato colocalizes with GFP-Rac1 (arrowhead) in the periphery of C2C12 cells but not in cytoplasmic vesicles. Bar, 5 µm. (B) Rac1 activation assay of mouse primary myoblasts transduced with Wnt7a-HA (Wnt7a) retrovirus or an empty control virus (EV). In addition, all cells were either treated with an siRNA SMARTpool targeting Dvl2 (siDvl2) or with a scrambled control (siSCR). Total Rac1 is shown as a loading control. (C) Coimmunoprecipitation of Rac1 with Dvl2 in primary myoblasts that were infected with Wnt7a or EV. More Rac1 associates with Dvl2 in Wnt7a-expressing cells. (D) Scratch assay with mouse primary myoblasts that were Wnt7a or vehicle treated. The cells were also transfected with either siSCR or siDvl2. Error bars represent means ± SEM; n = 3. *, P < 0.05. n.s., no significant difference. (E) Scratch assay with mouse primary myoblasts that overexpress EV or Fzd7-Flag and that were treated with siDvl2 or siSCR. Error bars represent means ± SEM; n = 3. *, P < 0.05. (F) Dominant-negative Rac1 (Rac1-DN) prevents Wnt7a-induced mouse primary myoblast migration in scratch assays. Error bars represent means ± SEM; n = 3. **, P < 0.01. (G) Rac1-DN prevents Fzd7-Flag–induced mouse primary myoblast migration in scratch assays. Error bars represent means ± SEM; n = 3. *, P < 0.05.