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 epithelial sheet. Several studies have identified genetic and cell biological mechanisms underlying extrusion and delamination 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 quantitative physical modeling to characterize forces driving emergence of a new apical surface as nascent cells are added to a vertebrate epithelium in vivo. We find that this process involves an interplay between cell-autonomous actin-generated forces in the emerging cell and the mechanical properties of neighboring cells. Our findings define the forces driving a novel cell behavior, and by complementing previous studies of delamination and extrusion, they provide a more comprehensive understanding of epithelial homeostasis.
Tags: Apical, Epithelium, Cell biology, Biology, Uterine epithelium, Epithelial polarity
Annonce publiée le 14-08-2018
Centre de Recherche - Paris - Amphitheatre Biologie du developpement et cancer