PUBLICATION

Mtx2 directs zebrafish morphogenetic movements during epiboly by regulating microfilament formation

Authors
Wilkins, S.J., Yoong, S., Verkade, H., Mizoguchi, T., Plowman, S.J., Hancock, J.F., Kikuchi, Y., Heath, J.K., and Perkins, A.C.
ID
ZDB-PUB-071227-13
Date
2008
Source
Developmental Biology   314(1): 12-22 (Journal)
Registered Authors
Heath, Joan K., Kikuchi, Yutaka, Mizoguchi, Takamasa, Verkade, Heather, Wilkins, Simon
Keywords
Epiboly, Mtx2, Mxtx2, Gastrulation, Morphogenetic movements, Yolk syncytial layer (YSL), Zebrafish, Endoderm, Microfilaments, F-actin
MeSH Terms
  • Actin Cytoskeleton/physiology*
  • Actins/physiology*
  • Animals
  • Cell Movement/physiology
  • DNA-Binding Proteins/genetics
  • DNA-Binding Proteins/physiology
  • Embryo, Nonmammalian
  • Gastrulation/physiology
  • High Mobility Group Proteins/genetics
  • High Mobility Group Proteins/physiology
  • Membrane Proteins/physiology*
  • Promoter Regions, Genetic
  • SOXF Transcription Factors
  • Transcription Factors/genetics
  • Transcription Factors/physiology
  • Zebrafish/embryology
  • Zebrafish/physiology*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/physiology*
PubMed
18154948 Full text @ Dev. Biol.
Abstract
The homeobox transcription factor Mtx2 is essential for epiboly, the first morphogenetic movement of gastrulation in zebrafish. Morpholino knockdown of Mtx2 results in stalling of epiboly and lysis due to yolk rupture. However, the mechanism of Mtx2 action is unknown. The role of mtx2 is surprising as most mix/bix family genes are thought to have roles in mesendoderm specification. Using a transgenic sox17-promoter driven EGFP line, we show that Mtx2 is not required for endoderm specification but is required for correct morphogenetic movements of endoderm and axial mesoderm. During normal zebrafish development, mtx2 is expressed at both the blastoderm margin and in the zebrafish equivalent of visceral endoderm, the extra-embryonic yolk syncytial layer (YSL). We show that formation of the YSL is not Mtx2 dependent, but that Mtx2 directs spatial arrangement of YSL nuclei. Furthermore, we demonstrate that Mtx2 knockdown results in loss of the YSL F-actin ring, a microfilament structure previously shown to be necessary for epiboly progression. In summary, we propose that Mtx2 acts within the YSL to regulate morphogenetic movements of both embryonic and extra-embryonic tissues, independently of cell fate specification.
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