Myosin-II-mediated cell shape changes and cell intercalation contribute to primitive streak formation

Nat Cell Biol. 2015 Apr;17(4):397-408. doi: 10.1038/ncb3138.


Primitive streak formation in the chick embryo involves large-scale highly coordinated flows of more than 100,000 cells in the epiblast. These large-scale tissue flows and deformations can be correlated with specific anisotropic cell behaviours in the forming mesendoderm through a combination of light-sheet microscopy and computational analysis. Relevant behaviours include apical contraction, elongation along the apical-basal axis followed by ingression, and asynchronous directional cell intercalation of small groups of mesendoderm cells. Cell intercalation is associated with sequential, directional contraction of apical junctions, the onset, localization and direction of which correlate strongly with the appearance of active myosin II cables in aligned apical junctions in neighbouring cells. Use of class specific myosin inhibitors and gene-specific knockdown shows that apical contraction and intercalation are myosin II dependent and also reveal critical roles for myosin I and myosin V family members in the assembly of junctional myosin II cables.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Cell Line
  • Cell Movement
  • Cell Proliferation
  • Cell Shape / physiology*
  • Chick Embryo
  • Chickens
  • Gastrulation / physiology
  • HEK293 Cells
  • Heterocyclic Compounds, 4 or More Rings / pharmacology
  • Humans
  • Hydrocarbons, Chlorinated / pharmacology
  • Myosin Type I / antagonists & inhibitors
  • Myosin Type I / genetics
  • Myosin Type I / metabolism*
  • Myosin Type II / antagonists & inhibitors
  • Myosin Type II / genetics
  • Myosin Type II / metabolism*
  • Myosin Type V / antagonists & inhibitors
  • Myosin Type V / genetics
  • Myosin Type V / metabolism*
  • Phosphorylation
  • Primitive Streak / cytology
  • Primitive Streak / embryology*
  • Pyrroles / pharmacology
  • RNA Interference
  • RNA, Small Interfering


  • Heterocyclic Compounds, 4 or More Rings
  • Hydrocarbons, Chlorinated
  • Pyrroles
  • RNA, Small Interfering
  • pentabromopseudilin
  • pentachloropseudilin
  • blebbistatin
  • Myosin Type I
  • Myosin Type II
  • Myosin Type V