Two different mechanisms of planar cell intercalation leading to tissue elongation.
During development, certain cells intercalate with each other towards tissue-elongation, exemplified in sea-urchin gut-elongation, amphibian gastrulation, and Drosophila germ-band extension. Their mechanism is not universal among intercalation events. To clarify the minimal cellular properties required for cell-intercalation, we computer-simulated the process using three-dimensional geometrical cell-models. We identified two different mechanisms: (1) cell-junction-remodeling by cell-junction contraction along a specific direction, as observed in Drosophila germ-band extension, and (2) cell-shuffling by orientated cell-extension of bipolar cells, as observed in amphibian gastrulation. The cell-junction-remodeling was characterized by well-defined accumulation of contractile molecules along a specific direction of cell-junctions. Length contraction of approximately one cell-junction per cell is enough for the entire tissue-elongation. The cell-shuffling was characterised by rhythmic cell-extension and orientated movement of cytoskeleton within the elongated cells. Furthermore, tissue-elongation along a polarized axis was limited to a 2.5-fold increase in the cell-junction-remodeling, while no limit was defined for the cell-shuffling.
Hyogo University, Kakogawa, Hyogo, Japan. hihonda@hyogo-dai.ac.jp
Hisao
H
Honda
Tatsuzo
T
Nagai
Masaharu
M
Tanemura
D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology; D003198:Computer Simulation; D004331:Drosophila melanogaster; D005775:Gastrula / Q000166:cytology*; D021621:Imaging, Three-Dimensional; D008954:Models, Biological; D012617:Sea Urchins