Signals for death and survival: a two-step mechanism for cavitation in the vertebrate embryo.
Conversion of a solid primordium to a hollow tube of cells is a morphogenetic process used frequently during vertebrate embryogenesis. In the early mouse embryo, this process of cavitation transforms the solid embryonic ectoderm into a columnar epithelium surrounding a cavity. Using both established cell lines and normal embryos, we provide evidence that cavitation in the early mouse embryo is the result of the interplay of two signals, one from an outer layer of endoderm cells that acts over short distances to create a cavity by inducing apoptosis of the inner ectodermal cells, and the other a rescue signal mediated by contact with the basement membrane that is required for the survival of the columnar cells that line the cavity. This simple model provides a paradigm for investigating tube morphogenesis in diverse developmental settings.
Coucouvanis
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Department of Anatomy, School of Medicine, University of California at San Francisco 94143-0452, USA.
Martin
G R
GR
D000650:Amnion / Q000254:growth & development; D000818:Animals; D017209:Apoptosis; D001755:Blastocyst / Q000502:physiology; D002450:Cell Communication; D002678:Chimera; D004475:Ectoderm / Q000502:physiology; D004627:Embryonic Induction; D005314:Embryonic and Fetal Development; D004707:Endoderm / Q000502:physiology; D004848:Epithelium / Q000196:embryology; D005109:Extracellular Matrix / Q000502:physiology; D051379:Mice; D008954:Models, Biological; D051381:Rats; D013234:Stem Cells; D018243:Teratocarcinoma; D014407:Tumor Cells, Cultured; D014781:Viscera / Q000196:embryology