Distinct apical and basolateral mechanisms drive planar cell polarity-dependent convergent extension of the mouse neural plate.
The mechanisms of tissue convergence and extension (CE) driving axial elongation in mammalian embryos, and in particular, the cellular behaviors underlying CE in the epithelial neural tissue, have not been identified. Here we show that mouse neural cells undergo mediolaterally biased cell intercalation and exhibit both apical boundary rearrangement and polarized basolateral protrusive activity. Planar polarization and coordination of these two cell behaviors are essential for neural CE, as shown by failure of mediolateral intercalation in embryos mutant for two proteins associated with planar cell polarity signaling: Vangl2 and Ptk7. Embryos with mutations in Ptk7 fail to polarize cell behaviors within the plane of the tissue, whereas Vangl2 mutant embryos maintain tissue polarity and basal protrusive activity but are deficient in apical neighbor exchange. Neuroepithelial cells in both mutants fail to apically constrict, leading to craniorachischisis. These results reveal a cooperative mechanism for cell rearrangement during epithelial morphogenesis.
Department of Cell Biology; University of Virginia, Charlottesville, VA 22908, USA.
Margot
M
Williams
Department of Cell Biology; University of Virginia, Charlottesville, VA 22908, USA.
Weiwei
W
Yen
Department of Cell Biology; University of Virginia, Charlottesville, VA 22908, USA.
Xiaowei
X
Lu
Department of Cell Biology; University of Virginia, Charlottesville, VA 22908, USA. Electronic address: as9n@virginia.edu.
Ann
A
Sutherland
D000818:Animals; D002454:Cell Differentiation; D002465:Cell Movement; D016764:Cell Polarity; D051379:Mice; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D054258:Neural Plate / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D058953:Neural Stem Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D046569:Neuroepithelial Cells / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism
C431577:Ltap protein, mouse; D009419:Nerve Tissue Proteins; C486452:Ptk7 protein, mouse; D020794:Receptor Protein-Tyrosine Kinases