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Wnt signaling and the evolution of pattern formation
Author(s) -
Wikramanayake Athula H,
Kumburegama Shalika,
Peng Jeff,
Wijeseveen
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.308.3
Subject(s) - gastrulation , dishevelled , wnt signaling pathway , biology , microbiology and biotechnology , blastula , germ layer , morphogenesis , convergent extension , frizzled , signal transduction , embryo , embryogenesis , genetics , embryonic stem cell , gene , induced pluripotent stem cell
Evolution of gastrulation was crucial for metazoan diversification, but the molecular origins of developmental polarity that led to the onset of gastrulation mechanisms are unknown. Nuclear ß‐catenin marks the site of gastrulation in cnidarians and several bilaterians, raising the possibility that evolution of mechanisms to asymmetrically activate Wnt signaling in embryos may have been causal in evolution of gastrulation. We have shown that localized activation of Dishevelled (Dsh), a key regulator of Wnt/ß ‐catenin signaling, plays a crucial role in germ layer segregation and gastrulation in sea urchins and in the cnidarian Nematostella vectensis. Dsh also regulates the Wnt/Planar Cell Polarity (PCP) pathway, which mediates vertebrate gastrulation movements. In Nematostella, blocking Dsh signaling in the PCP pathway, or blocking Strabismus function using morpholinos blocks gastrulation, suggesting that Wnt/PCP signaling mediated gastrulation movements in the last common ancestor to cnidarians and bilaterians. Because Dsh can regulate multiple Wnt pathways, it may have been a critical link between evolution of cell fate specification and evolution of gastrulation morphogenesis. Our results also support the hypothesis that one ancient function of PCP signaling was to mediate the developmental asymmetry that led to the evolution of gastrulation. (Supported by NSF grants IOS 0720365 and IOS 0754323)