Analysis of Xenopus frizzleds

Wnts are secreted signaling molecules implicated in a large number of developmental processes. Frizzled proteins have been identified as likely receptors for Wnt ligands in vertebrates and invertebrates. To assess the endogenous role of frizzled proteins during the development of vertebrates, we have identified several Xenopus laevis frizzled homologs (xfz\u27s). In this work we report on xfz8, xfz3 and xfz2. Xfz8 is expressed in the Spemann organizer, is capable of inducing ectopic dorsal axes in Xenopus, and plays a role in coordinating the morphogenetic movements of gastrulation. Xfz2 is expressed in the eye, otic vesicle and somites and may play roles in the development of these tissues. In a larger screen to identify specificity between wnts and frizzleds, we identified an interaction between xfz3 and Wnt-1. Endogenously, xfz3 may play a role with Wnt-1 in the induction of neural crest. Our work is one of the first to suggest possible roles for frizzleds in vertebrate development