title: Emergence of an Apical Epithelial Cell Surface In Vivo.
abstract: Epithelial sheets are crucial components of all metazoan animals, enclosing organs and protecting the animal from its environment. Epithelial homeostasis poses unique challenges, as addition of new cells and loss of old cells must be achieved without disrupting the fluid-tight barrier and apicobasal polarity of the epithelium. Several studies have identified cell biological mechanisms underlying extrusion of cells from epithelia, but far less is known of the converse mechanism by which new cells are added. Here, we combine molecular, pharmacological, and laser-dissection experiments with theoretical modeling to characterize forces driving emergence of an apical surface as single nascent cells are added to a vertebrate epithelium in vivo. We find that this process involves the interplay between cell-autonomous actin-generated pushing forces in the emerging cell and mechanical properties of neighboring cells. Our findings define the forces driving this cell behavior, contributing to a more comprehensive understanding of epithelial homeostasis.
authors.affiliation: Department of Molecular Biosciences, Center for Systems and Synthetic Biology, and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Jakub
authors.initials: J
authors.lastname: Sedzinski
authors.affiliation: Cavendish Laboratory, Department of Physics, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UK; Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK.
authors.forename: Edouard
authors.initials: E
authors.lastname: Hannezo
authors.affiliation: Department of Molecular Biosciences, Center for Systems and Synthetic Biology, and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Fan
authors.initials: F
authors.lastname: Tu
authors.affiliation: Centenary Institute of Cancer Medicine and Cell Biology, Locked Bag 6, Newtown, NSW 2042, Australia; Sydney Medical School, The University of Sydney, Sydney, NSW 2006, Australia.
authors.forename: Maté
authors.initials: M
authors.lastname: Biro
authors.affiliation: Department of Molecular Biosciences, Center for Systems and Synthetic Biology, and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA; Patterson Labs, University of Texas, 2401 Speedway, Austin, TX 78712, USA. Electronic address: wallingford@austin.utexas.edu.
authors.forename: John B
authors.initials: JB
authors.lastname: Wallingford
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002469:Cell Separation / Q000379:methods; D004847:Epithelial Cells / Q000166:cytology*; D004848:Epithelium / Q000378:metabolism*; D006706:Homeostasis / Q000502:physiology*; D019108:Tight Junctions / Q000378:metabolism*; D014981:Xenopus
chemical_list: D000199:Actins