Wnt signaling in axial patterning and regeneration: lessons from planaria.
Wnt signal transduction plays a crucial role in stem cell proliferation and regeneration. When canonical Wnt signaling is low, heads develop, and when it is high, tails are formed. In planarians, Wnt transcription is activated by wounding in a beta-catenin-independent way. Hedgehog is one of the signals involved, because it induces regeneration of tails (instead of heads) through the activation of Wnt transcription. Depletion of Smad4 blocks regeneration entirely, which suggests that the bone morphogenetic protein signaling pathway and the Wnt pathway are required for regeneration and body patterning.
De Robertis
Edward M
EM
Howard Hughes Medical Institute and Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, CA 90095-1662, USA. ederobertis@mednet.ucla.edu
D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D002455:Cell Division; D006257:Head / Q000502:physiology; D006706:Homeostasis; D009024:Morphogenesis / Q000502:physiology; D010932:Planarians / Q000033:anatomy & histology / Q000502:physiology*; D012038:Regeneration / Q000502:physiology*; D015398:Signal Transduction; D013623:Tail / Q000502:physiology; D051153:Wnt Proteins / Q000502:physiology*
D051153:Wnt Proteins