ZFIN ID: ZDB-PUB-070813-9
Wnt/Axin1/beta-Catenin Signaling Regulates Asymmetric Nodal Activation, Elaboration, and Concordance of CNS Asymmetries
Carl, M., Bianco, I.H., Bajoghli, B., Aghaallaei, N., Czerny, T., and Wilson, S.W.
Date: 2007
Source: Neuron   55(3): 393-405 (Journal)
Registered Authors: Aghaallaei, Narges, Bajoghli, Baubak, Bianco, Isaac, Carl, Matthias, Wilson, Steve
Keywords: none
MeSH Terms:
  • Animals
  • Axin Protein
  • Dominance, Cerebral/physiology*
  • Epithalamus/embryology
  • Epithalamus/metabolism
  • Functional Laterality/physiology
  • Gastrula/physiology
  • Gene Expression
  • Habenula/cytology
  • Habenula/embryology
  • Mesoderm/metabolism
  • Mutation
  • Neurons/cytology
  • Nodal Protein
  • Prosencephalon/embryology*
  • Protein Isoforms/genetics
  • Protein Isoforms/physiology
  • Repressor Proteins/genetics
  • Repressor Proteins/physiology*
  • Signal Transduction/physiology
  • Tissue Distribution/physiology
  • Transforming Growth Factor beta/genetics
  • Transforming Growth Factor beta/physiology*
  • Wnt Proteins/physiology*
  • Zebrafish/embryology*
  • beta Catenin/physiology*
PubMed: 17678853 Full text @ Neuron
Nodal activity in the left lateral plate mesoderm (LPM) is required to activate left-sided Nodal signaling in the epithalamic region of the zebrafish forebrain. Epithalamic Nodal signaling subsequently determines the laterality of neuroanatomical asymmetries. We show that overactivation of Wnt/Axin1/beta-catenin signaling during late gastrulation leads to bilateral epithalamic expression of Nodal pathway genes independently of LPM Nodal signaling. This is consistent with a model whereby epithalamic Nodal signaling is normally bilaterally repressed, with Nodal signaling from the LPM unilaterally alleviating repression. We suggest that Wnt signaling regulates the establishment of the bilateral repression. We identify a second role for the Wnt pathway in the left/right regulation of LPM Nodal pathway gene expression, and finally, we show that at later stages Axin1 is required for the elaboration of concordant neuroanatomical asymmetries.