1. Morphogenesis of the primitive gut tube is generated by Rho/ROCK/myosin II-mediated endoderm rearrangements.
- Author
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Reed RA, Womble MA, Dush MK, Tull RR, Bloom SK, Morckel AR, Devlin EW, and Nascone-Yoder NM
- Subjects
- Animals, Animals, Genetically Modified, Body Patterning genetics, Cell Polarity genetics, Cell Shape genetics, Embryo, Nonmammalian, Endoderm cytology, Endoderm metabolism, Gastrointestinal Diseases congenital, Gastrointestinal Diseases embryology, Gastrointestinal Tract abnormalities, Gastrointestinal Tract embryology, Gastrula metabolism, Models, Biological, Nonmuscle Myosin Type IIB genetics, Nonmuscle Myosin Type IIB metabolism, Signal Transduction genetics, Xenopus embryology, Xenopus genetics, Xenopus metabolism, rho-Associated Kinases genetics, rho-Associated Kinases metabolism, rhoA GTP-Binding Protein genetics, rhoA GTP-Binding Protein metabolism, Endoderm embryology, Gastrula embryology, Morphogenesis genetics, Nonmuscle Myosin Type IIB physiology, rho-Associated Kinases physiology, rhoA GTP-Binding Protein physiology
- Abstract
During digestive organogenesis, the primitive gut tube (PGT) undergoes dramatic elongation and forms a lumen lined by a single-layer of epithelium. In Xenopus, endoderm cells in the core of the PGT rearrange during gut elongation, but the morphogenetic mechanisms controlling their reorganization are undetermined. Here, we define the dynamic changes in endoderm cell shape, polarity, and tissue architecture that underlie Xenopus gut morphogenesis. Gut endoderm cells intercalate radially, between their anterior and posterior neighbors, transforming the nearly solid endoderm core into a single layer of epithelium while concomitantly eliciting "radially convergent" extension within the gut walls. Inhibition of Rho/ROCK/Myosin II activity prevents endoderm rearrangements and consequently perturbs both gut elongation and digestive epithelial morphogenesis. Our results suggest that the cellular and molecular events driving tissue elongation in the PGT are mechanistically analogous to those that function during gastrulation, but occur within a novel cylindrical geometry to generate an epithelial-lined tube., ((c) 2009 Wiley-Liss, Inc.)
- Published
- 2009
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