PUBLICATION

The Cell Adhesion-associated Protein Git2 Regulates Morphogenetic Movements during Zebrafish Embryonic Development

Authors
Yu, J.A., Foley, F.C., Amack, J.D., and Turner, C.E.
ID
ZDB-PUB-101108-1
Date
2011
Source
Developmental Biology   349(2): 225-237 (Journal)
Registered Authors
Amack, Jeffrey, Foley, Fiona
Keywords
Zebrafish, Epiboly, Gastrulation, Git2, Non-muscle Myosin II, Blebbistatin, Paxillin, FAK
MeSH Terms
  • Animals
  • Base Sequence
  • Cell Adhesion Molecules/metabolism*
  • Cell Movement/physiology*
  • Embryonic Development/physiology*
  • GTPase-Activating Proteins/genetics
  • GTPase-Activating Proteins/metabolism*
  • Gene Knockdown Techniques
  • Heterocyclic Compounds, 4 or More Rings
  • Immunoblotting
  • Immunohistochemistry
  • In Situ Hybridization
  • Molecular Sequence Data
  • Morphogenesis/physiology*
  • Myosin Light Chains/metabolism
  • Phosphorylation
  • Phylogeny
  • Sequence Analysis, DNA
  • Signal Transduction/physiology*
  • Time-Lapse Imaging
  • Zebrafish/embryology*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
PubMed
21034731 Full text @ Dev. Biol.
Abstract
Signaling through cell adhesion complexes plays a critical role in coordinating cytoskeletal remodeling necessary for efficient cell migration. During embryonic development, normal morphogenesis depends on a series of concerted cell movements; but the roles of cell adhesion signaling during these movements are poorly understood. The transparent zebrafish embryo provides an excellent system to study cell migration during development. Here, we have identified zebrafish git2a and git2b, two new members of the GIT family of genes that encode ArfGAP proteins associated with cell adhesions. Loss-of-function studies revealed an essential role for Git2a in zebrafish cell movements during gastrulation. Time-lapse microscopy analysis demonstrated that antisense depletion of Git2a greatly reduced or arrested cell migration towards the vegetal pole of the embryo. These defects were rescued by expression of chicken GIT2, indicating a specific and conserved role for Git2 in controlling embryonic cell movements. Git2a knockdown embryos showed defects in cell morphology that were associated with reduced cell contractility. We show that Git2a is required for phosphorylation of myosin light chain (MLC), which regulates myosin II-mediated cell contractility. Consistent with this, embryos treated with Blebbistatin-a small molecule inhibitor for myosin II activity-exhibited cell movement defects similar to git2a knockdown embryos. These observations provide in vivo evidence of a physiologic role for Git2a in regulating cell morphogenesis and directed cell migration via myosin II activation during zebrafish embryonic development.
Genes / Markers
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping