Fig. 11. Implantation of Fgf4-soaked beads into ext2/dak and extl3/box embryos. Dorsal (A-C) and lateral (A'-C'') views of 2.5-day-old embryos, anterior towards the left. Expression of genes was examined by in situ hybridisation in operated left-hand side (A'-C') and unoperated right-hand side fin buds (A''-C''). Fgf4 protein beads strongly rescued the expression of eng1a (A-A'') and wnt7a (B-B'') in ext2/dak mutant embryos. Similarly, shh (C-C'') expression was rescued in extl3/box following implantation of Fgf4-soaked beads. Yellow asterisks indicate position of implanted beads (A'-C'). LV, left view of embryo; RV, right view of same embryo.