From cells to tissue: decoupling cell-adhesion and contractile forces in a model epithelial tissue framework*

Epithelial cells in monolayers undergo rearrangements, also known as T1 transitions that facilitate their motility during various developmental processes. Such rearrangements are a result of many cellular properties as well as their interactions. It is difficult to isolate the effects of such properties in Vertex/Voronoi-based models of epithelial tissues, as a cell cannot be defined in isolation and there is a lack of control over the various dynamics of individual cells and their interactions.

Here, we propose a framework to model epithelial cells and tissues as deformable polygons(DP) with precise control over single-cell properties such as their elasticity, surface tension, and motility as well as their interactions in a dense 2D monolayer. Here, the tissue is not constrained to be confluent, and the effect of cell-cell adhesion and cell shapes are decoupled. We identify the jamming onset for the DP model and simulate the effect of cell motion in temperature-controlled dynamics. Our results reveal that increased cell-cell adhesion slows cell dynamics via caging effects above the jamming density. In contrast, reduced cell contractility promotes cell diffusion by increasing available free space for diffusion.