Fig. 4. Mis-expression of a stabilized version of ß-catenin using RCAS virus in cranial neural crest cells. The 'exclusion' function of Adobe PhotoShop was used to demonstrate the overlap (red) between pigments cells (black) and smooth muscle cells (blue) in non-infected crest cell cultures (A) or cultures infected (B) with RCAS::ß-catenin virus, both treated with FGF2. Note that the relative ratios of smooth muscle cells and pigmented cells are dramatically different.