PUBLICATION

The zebrafish nodal-related gene southpaw is required for visceral and diencephalic left-right asymmetry

Authors
Long, S., Ahmad, N., and Rebagliati, M.
ID
ZDB-PUB-030425-22
Date
2003
Source
Development (Cambridge, England)   130(11): 2303-2316 (Journal)
Registered Authors
Ahmad, Nadira, Rebagliati, Michael
Keywords
none
MeSH Terms
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Body Patterning/genetics
  • DNA, Complementary/genetics
  • Diencephalon/embryology*
  • Gene Expression Regulation, Developmental
  • Heart Defects, Congenital/embryology
  • Heart Defects, Congenital/genetics
  • In Situ Hybridization
  • Mesoderm/cytology
  • Models, Biological
  • Molecular Sequence Data
  • Mutation
  • Nodal Protein
  • Oligodeoxyribonucleotides, Antisense/genetics
  • Oligodeoxyribonucleotides, Antisense/pharmacology
  • Organizers, Embryonic/embryology
  • Pancreas/embryology
  • Sequence Homology, Amino Acid
  • Transforming Growth Factor beta/genetics
  • Zebrafish/embryology*
  • Zebrafish/genetics*
  • Zebrafish Proteins/genetics
PubMed
12702646 Full text @ Development
Abstract
We have identified and characterized a new zebrafish gene, southpaw, that is required for visceral and diencephalic left-right asymmetry. southpaw encodes a new member of the nodal-related class of proteins, a subfamily within the transforming growth factor beta superfamily of secreted factors. southpaw is expressed bilaterally in paraxial mesoderm precursors and then within the left lateral plate mesoderm. At late somite stages, left-sided southpaw expression transiently overlaps the left-sided expression domains of other genes that mark the developing heart, such as lefty2. We have injected morpholinos to block the translation of the southpaw mRNA or to block splicing of the southpaw pre-mRNA. These morpholinos cause a severe disruption of early (cardiac jogging) and late (cardiac looping) aspects of cardiac left-right asymmetry. As the left-right asymmetry of the pancreas is also affected , southpaw appears to regulate left-right asymmetry throughout a large part of the embryo. Consistent with the morphological changes, the left- sided expression domains of downstream genes (cyclops, pitx2, lefty1 and lefty2) are severely downregulated or abolished within the lateral plate mesoderm of Southpaw-deficient embryos. Surprisingly, despite the absence of southpaw expression in the brain, we find that early diencephalic left-right asymmetry also requires Southpaw activity. These observations lead to a model of how visceral organ and brain left-right asymmetry are coordinated during embryogenesis.
Genes / Markers
Figures
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Expression
Phenotype
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping
Errata and Notes