PUBLICATION

Differentiation of cerebellar cell identities in absence of Fgf signalling in zebrafish Otx morphants

Authors
Foucher, I., Mione, M., Simeone, A., Acampora, D., Bally-Cuif, L., and Houart, C.
ID
ZDB-PUB-060419-2
Date
2006
Source
Development (Cambridge, England)   133(10): 1891-1900 (Journal)
Registered Authors
Bally-Cuif, Laure, Foucher, Isabelle, Houart, Corinne, Mione, Marina
Keywords
Cerebellum, Fgf8, Otx2, Isthmic organiser
MeSH Terms
  • Pyrroles/pharmacology
  • Embryo, Nonmammalian
  • Signal Transduction/drug effects
  • Cell Proliferation
  • Fibroblast Growth Factors/metabolism
  • Cerebellum/cytology*
  • Cerebellum/embryology
  • Zebrafish/embryology*
  • Zebrafish/metabolism
  • Otx Transcription Factors/metabolism*
  • Rhombencephalon/embryology
  • Oligonucleotides, Antisense/pharmacology
  • Mutation
  • Microinjections
  • Cell Differentiation*
  • Mesencephalon/embryology
  • Animals
  • Fibroblast Growth Factor 8/metabolism
  • Zebrafish Proteins/metabolism*
(all 19)
PubMed
16611693 Full text @ Development
Abstract
Although the secreted molecule Fgf8 is a key player of the isthmic organiser function, the mechanisms by which it acts remain unclear. Here, we present evidence indicating that Fgf8 is not instructive in establishing zebrafish cerebellar cell identities, although it is required for proliferation and morphogenesis of this territory. We first show that, as in mouse, lack of Otx function in zebrafish leads to transformation of the presumptive mesencephalon into an extended rhombomere 1 (r1). Expanded Fgf8 expression was proposed to be the cause of this fate transformation. However, this report demonstrates that zebrafish embryos lacking both Otx and fgf8 functions retain an extended r1 and display differentiation of at least two cerebellar cell fates. We show that this is not caused by presence of other Fgfs, which implies that in absence of Otx, Fgf function is not necessary for the differentiation of cerebellar cell types. Otx proteins are therefore potent repressors of cerebellar fates, kept out of r1 progeny by Fgf8. Because Otx transcripts are not present in presumptive r1 territory prior to fgf8 expression, Fgf8 is required to maintain, rather than induce, the posterior boundary of Otx expression. This maintenance is enough to allow cerebellar differentiation.
Genes / Markers
Figures
Figure Gallery (10 images)
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Expression
Phenotype
No data available
Mutations / Transgenics
Allele Construct Type Affected Genomic Region
ne1939TgTransgenic Insertion
    ti282a
      		Point Mutation
      1 - 2 of 2
      Show
      Human Disease / Model
      No data available
      Sequence Targeting Reagents
      Target Reagent Reagent Type
      otx1MO2-otx1MRPHLNO
      otx1MO3-otx1MRPHLNO
      otx1MO4-otx1MRPHLNO
      otx2aMO1-otx2aMRPHLNO
      otx2bMO1-otx2bMRPHLNO
      1 - 5 of 5
      Show
      Fish
      Fish
      fgf8ati282a/ti282a
      fgf8ati282a/ti282a + MO1-otx2a + MO1-otx2b
      ne1939Tg
      WT
      WT + MO1-otx2a + MO1-otx2b
      1 - 5 of 5
      Show
      Antibodies
      No data available
      Orthology
      No data available
      Engineered Foreign Genes
      No data available
      Mapping
      No data available
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      Citation
      Foucher, I., Mione, M., Simeone, A., Acampora, D., Bally-Cuif, L., and Houart, C. (2006) Differentiation of cerebellar cell identities in absence of Fgf signalling in zebrafish Otx morphants. Development (Cambridge, England). 133(10):1891-1900.