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ZFIN ID: ZDB-PUB-001107-1
Asymmetric Nodal signaling in the zebrafish diencephalon positions the pineal organ
Liang, J.O., Etheridge, A., Hantsoo, L., Rubinstein, A.L., Nowak, S.J., Izpisúa Belmonte, J.C., and Halpern, M.E.
Date: 2000
Source: Development (Cambridge, England)   127(23): 5101-5112 (Journal)
Registered Authors: Halpern, Marnie E., Izpisúa Belmonte, Juan Carlos, Liang, Jennifer, Rubinstein, Amy
Keywords: pineal organ; nodal; left-right axis; zebrafish
MeSH Terms:
  • Animals
  • Body Patterning/physiology*
  • Brain/embryology
  • Diencephalon/embryology
  • Endoderm
  • Epiphyses
  • Female
  • Gene Expression Regulation, Developmental*
  • Homeodomain Proteins/genetics*
  • Intracellular Signaling Peptides and Proteins
  • Left-Right Determination Factors
  • Male
  • Mutagenesis
  • Nodal Protein
  • Nuclear Proteins*
  • Paired Box Transcription Factors
  • Pineal Gland/embryology*
  • Prosencephalon/embryology
  • Signal Transduction/genetics*
  • Transcription Factors/genetics*
  • Transforming Growth Factor beta/genetics*
  • Zebrafish/embryology
  • Zebrafish/genetics
  • Zebrafish Proteins*
PubMed: 11060236
ABSTRACT
The vertebrate brain develops from a bilaterally symmetric neural tube but later displays profound anatomical and functional asymmetries. Despite considerable progress in deciphering mechanisms of visceral organ laterality, the genetic pathways regulating brain asymmetries are unknown. In zebrafish, genes implicated in laterality of the viscera (cyclops/nodal, antivin/lefty and pitx2) are coexpressed on the left side of the embryonic dorsal diencephalon, within a region corresponding to the presumptive epiphysis or pineal organ. Asymmetric gene expression in the brain requires an intact midline and Nodal-related factors. RNA-mediated rescue of mutants defective in Nodal signaling corrects tissue patterning at gastrulation, but fails to restore left-sided gene expression in the diencephalon. Such embryos develop into viable adults with seemingly normal brain morphology. However, the pineal organ, which typically emanates at a left-to-medial site from the dorsal diencephalic roof, becomes displaced in position. Thus, a conserved signaling pathway regulating visceral laterality also underlies an anatomical asymmetry of the zebrafish forebrain.
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