1ST experiment exploiting the Wnt pathway
1. The authors first look to see if the Wnts studied act through the canonical Wnt/β-catenin pathway, which leads to the activation of β-catenin. They conduct a western blot in order to visualize if β-catenin protein is present in the cytosol of chick embryos that have been injected with a retrovirus for the Wnts of interest. Results show that these Wnts do in fact utilize the canonical Wnt/β-catenin pathway by interacting to the cell membrane receptor, resulting in the activation of β-catenin, as the western blot shows cytosolic leveles of β-catenin present with these Wnts. The authors then inject embryos with a retrovirus encoding the activated form of β-catenin into the flank of embryos. The embryos are allowed to develop and then, through a skeletal staining, ectopic limbs were observed. These Wnts, utilizing the Wnt pathway to activate β-catenin, are therefore SUFFICIENT in ectopic limb formation.