β-catenin-dependent wnt signaling in C. elegans: Teaching an old dog a new trick

Abstract

Wnt signaling is an evolutionarily ancient pathway used to regulate many events during metazoan development. Genetic results from Caenorhabditis elegans more than a dozen years ago suggested that Wnt signaling in this nematode worm might be different than in vertebrates and Drosophila: thewormhad a small number of Wnts, too manyβ-catenins, and some Wnt pathway components functioned in an opposite manner than in other species. Work over the ensuing years has clarified that C. elegans does possess a canonical Wnt/βcatenin signaling pathway similar to that in other metazoans, but that the majority of Wnt signaling in this species may proceed via a variant Wnt/b-catenin signaling pathway that uses some new components (mitogen-activated protein kinase signaling enzymes), and in which some conserved pathway components (β-catenin, T-cell factor [TCF]) are used in new and interestingways. This reviewsummarizes our current understanding of the canonical and novel TCF/β-catenin-dependent signaling pathways in C. elegans. © 2012 Cold Spring Harbor Laboratory Press; all rights reserved.