PUBLICATION

casanova plays an early and essential role in endoderm formation in zebrafish

Authors
Alexander, J., Rothenberg, M., Henry, G.L., and Stainier, D.Y.R.
ID
ZDB-PUB-991102-11
Date
1999
Source
Developmental Biology   215(2): 343-357 (Journal)
Registered Authors
Alexander, Jon, Stainier, Didier
Keywords
gut; axial; gata5; mixer; forerunner cells; Kupffer's vesicle; cardia bifida; endothelium; knypek; one-eyed pinhead
MeSH Terms
  • Amino Acid Sequence
  • Animals
  • Cell Differentiation
  • Endoderm/physiology*
  • Forkhead Transcription Factors
  • Gastrula/physiology
  • Genes, Homeobox
  • Mesoderm/physiology
  • Molecular Sequence Data
  • Morphogenesis/genetics
  • Transcription Factors/genetics
  • Zebrafish/embryology*
  • Zebrafish/genetics*
  • Zebrafish Proteins*
PubMed
10545242 Full text @ Dev. Biol.
Abstract
The cellular and molecular mechanisms that regulate endoderm development in vertebrates have only recently begun to be explored. Here we show that the zebrafish locus casanova plays an early and essential role in this process. casanova mutants lack a gut tube and do not express any molecular markers of endoderm differentiation. The early endodermal expression of genes such as axial, gata5, and fkd2 does not initiate in casanova mutants, indicating that the endoderm is defective from the onset of gastrulation. Mosaic analysis demonstrates that casanova functions cell autonomously within the endodermal progenitors. We also report the isolation of a zebrafish homologue of Mixer, a gene important for early endoderm formation in Xenopus. casanova does not encode zebrafish Mixer, and mixer expression is normal in casanova mutants, indicating that casanova acts downstream of, or parallel to, mixer to promote endoderm formation. We further find that the forerunner cells, a specialized group of noninvoluting dorsal mesendodermal cells, do not form in casanova mutants. Studies of casanova mutants do not support an important role for the forerunner cells in either dorsal axis or tail development, as has been previously proposed. In addition, although different populations of mesodermal precursors are generated normally in casanova mutants, morphogenetic defects in the heart, vasculature, blood, and kidney are apparent, suggesting a possible role for the endoderm in morphogenesis of these organs.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping