Cell Shape Dependent Motility During the Establishment of Tissue Structure

Mature epithelial tissues have distinct cellular architecture, which is maintained despite externally applied forces, wounding, and cell division or death. Here we investigate how a model tissue develops and maintains cellular structure by quantifying single cell dynamics and cell shape in newly formed MDCK monolayers. Over time cells in the monolayer become increasingly hexagonal and arrest at a final structure resembling a mature epithelium. Throughout this process we observe glassy dynamics controlled by cell shape, as predicted by vertex models. Varying substrate stiffness causes monolayers to form and evolve with different cell density, but a similar relationship between cell shape and dynamics. This suggests the changes in cell density often observed in tissue development may not directly impact cell motility. We find that inhibiting regulators of the actin cytoskeleton cause monolayers to arrest with elongated cell shapes. Interestingly, across a diverse set of conditions we find a relationship between the final cell shapes and velocity correlation length which we explore in vertex models by including cell alignment coupling. Our results demonstrate that multicellular coordination of motility affects the regulation of cell shape and determination of final tissue structure.