Regulation of cell migration during chick gastrulation.
Gastrulation in chick starts with large-scale cell flows in the epiblast and hypoblast, which transport the mesendoderm into the midline of the embryo to form the primitive streak. Several mechanisms such as cell-cell intercalation, deformations of the extracellular matrix and directed cell movements in response to chemical gradients have been proposed to play a role in streak formation. In the streak the epiblast cells undergo an epithelial to mesenchymal transition (EMT), which involves the breakdown of apical junctions and changes in RhoA-dependent signalling to integrins that mediated contact with the basal lamina. The collective migration of the mesendoderm away from the streak appears to be controlled by gradients of growth factors of the FGF and VEGF and Wnt families and requires N-cadherin expression. The timing and order of ingression of epiblast cells appears to be controlled by temporal and spatial colinearity of Hox gene expression in the epiblast. The mechanisms by which Hox genes control these properties remain to be resolved.
Chuai
Manli
M
Division of Cell and Developmental Biology, Wellcome Trust Biocentre, College of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kingdom.
Weijer
Cornelis Jan
CJ
D000818:Animals; D001485:Basement Membrane / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology*; D002642:Chick Embryo; D004847:Epithelial Cells / Q000378:metabolism*; D005346:Fibroblast Growth Factors / Q000378:metabolism; D054262:Gastrulation; D018507:Gene Expression Regulation, Developmental; D005855:Germ Layers / Q000166:cytology / Q000378:metabolism; D016023:Integrins / Q000378:metabolism; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D008954:Models, Biological; D054240:Primitive Streak / Q000166:cytology / Q000196:embryology; D015398:Signal Transduction; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D051153:Wnt Proteins / Q000378:metabolism
D016023:Integrins; D042461:Vascular Endothelial Growth Factor A; D051153:Wnt Proteins; D005346:Fibroblast Growth Factors