Insights into the Role of the Canonical Wnt Pathway in Embryonic Development

Abstract: Wnts are a family of proteins that control gene expression and cell differentiation, particularly in embryos. They serve a variety of roles in cell and tissue development, directing the creation and proliferation of embryonic cells and tissue layers, specifying the ectomesoderm and being instrumental in determining muscle cells. Wnt performs these functions through canonical and non-canonical pathways. The canonical Wnt pathway relies on beta-catenin to activate transcription factors that lead to the transcription of genes needed for cell and tissue differentiation. There are two non-canonical Wnt pathways, both independent of Beta-catenin: the planar cell polarity (PCP) pathway, which regulates cell orientation, and the Wnt/Ca2+ pathways, which involve the release of intracellular calcium. Wnts were initially thought to be long-range signalers, but a recent experiment with C. elegans used in-vitro signaling to suggest that Wnt also can spread locally. Wnt5 is a Wnt protein essential in border endoderm (BE) specification and embryonic tissue formation, making it critical in early embryonic development. A Wnt-endosome complex utilizes Wnt proteins to fine-tune Wnt signaling, controlling cell and tissue differentiation and development. Future research into Wnt may lead to developing therapies for cancers and degenerative diseases.