ABSTRACT
One spectacular phenotype in Xenopus embryos is obtained by modulating the maternal Wnt pathway, involved in early specification of the dorsoventral axis: inhibition of the pathway leads to loss of body axis, while its ectopic activation causes formation of a complete second body axis. The Wnt pathway regulates axis formation in Xenopus embryos. This chapter contains a short update on early induction in Xenopus and on the Wnt pathway, provides guidelines and strategies to characterize and analyze components of the Wnt pathway, and presents a selection of embryological, cell biological and molecular techniques useful for this purpose. It discusses the problems and limitations of the model, and the various strategies that have been devised to circumvent them.
