Fig. 4. The effects of Wnt overexpression on fibre-type differentiation in vitro. The bar chart shows the total number of differentiated myogenic cells, and the number expressing fast or slow MyHCs in 3-day limb micromass cultures that have been infected with either a control RCAS(BP) virus or retroviruses expressing Wnt3a, Wnt4, Wnt5a, Wnt6, Wnt7a, Wnt11 or Wnt14, as shown in Fig. 2. The slow population of myoblasts (red) might express either exclusively slow MyHC or both slow and fast MyHCs, whereas the fast myogenic population (yellow) only expresses fast MyHC isoforms. *, P<0.05; **, P<0.01; ***, P<0.001.