PUBLICATION

A novel role for MAPKAPK2 in morphogenesis during zebrafish development

Authors
Holloway, B.A., Gomez de la Torre Canny, S., Ye, Y., Slusarski, D.C., Freisinger, C.M., Dosch, R., Chou, M.M., Wagner, D.S., and Mullins, M.C.
ID
ZDB-PUB-090319-2
Date
2009
Source
PLoS Genetics   5(3): e1000413 (Journal)
Registered Authors
Dosch, Roland, Holloway, Beth A., Mullins, Mary C., Slusarski, Diane C., Wagner, Daniel
Keywords
Embryos, Blastoderm, Zebrafish, Actins, Cell membranes, Phenotypes, MAPK signaling cascades, Microtubules
MeSH Terms
  • Actins/metabolism
  • Animals
  • Calcium/metabolism
  • Cell Movement
  • Egg Yolk
  • Embryonic Development
  • Gastrula
  • Intracellular Signaling Peptides and Proteins/metabolism
  • Intracellular Signaling Peptides and Proteins/physiology*
  • Morphogenesis*
  • Mutant Proteins
  • Protein Serine-Threonine Kinases/metabolism
  • Protein Serine-Threonine Kinases/physiology*
  • Zebrafish/embryology
  • Zebrafish/growth & development*
  • p38 Mitogen-Activated Protein Kinases/metabolism
PubMed
19282986 Full text @ PLoS Genet.
Abstract
One of the earliest morphogenetic processes in the development of many animals is epiboly. In the zebrafish, epiboly ensues when the animally localized blastoderm cells spread, thin over, and enclose the vegetally localized yolk. Only a few factors are known to function in this fundamental process. We identified a maternal-effect mutant, betty boop (bbp), which displays a novel defect in epiboly, wherein the blastoderm margin constricts dramatically, precisely when half of the yolk cell is covered by the blastoderm, causing the yolk cell to burst. Whole-blastoderm transplants and mRNA microinjection rescue demonstrate that Bbp functions in the yolk cell to regulate epiboly. We positionally cloned the maternal-effect bbp mutant gene and identified it as the zebrafish homolog of the serine-threonine kinase Mitogen Activated Protein Kinase Activated Protein Kinase 2, or MAPKAPK2, which was not previously known to function in embryonic development. We show that the regulation of MAPKAPK2 is conserved and p38 MAP kinase functions upstream of MAPKAPK2 in regulating epiboly in the zebrafish embryo. Dramatic alterations in calcium dynamics, together with the massive marginal constrictive force observed in bbp mutants, indicate precocious constriction of an F-actin network within the yolk cell, which first forms at 50% epiboly and regulates epiboly progression. We show that MAPKAPK2 activity and its regulator p38 MAPK function in the yolk cell to regulate the process of epiboly, identifying a new pathway regulating this cell movement process. We postulate that a p38 MAPKAPK2 kinase cascade modulates the activity of F-actin at the yolk cell margin circumference allowing the gradual closure of the blastopore as epiboly progresses.
Genes / Markers
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Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping