Alignment interactions drive structural transitions in biological tissues

TL;DR

This study explores how alignment interactions between cell shape and motion influence tissue structure, revealing a transition from fluid to solid phases driven by nematic pattern formation.

Contribution

It introduces a model showing that alignment feedback induces a phase transition in tissue, highlighting the role of cell shape and motion feedback in tissue mechanics.

Findings

Alignment promotes nematic patterns in tissue.

A non-equilibrium phase transition to a solid occurs.

Highly asymmetric cells do not undergo this transition.

Abstract

Experimental evidence shows that there is a feedback between cell shape and cell motion. How this feedback impacts the collective behavior of dense cell monolayers remains an open question. We investigate the effect of a feedback that tends to align the cell crawling direction with cell elongation in a biological tissue model. We find that the alignment interaction promotes nematic patterns in the fluid phase that eventually undergo a non-equilibrium phase transition into a quasi-hexagonal solid. Meanwhile, highly asymmetric cells do not undergo the liquid-to-solid transition for any value of the alignment coupling. In this regime, the dynamics of cell centers and shape fluctuation show features typical of glassy systems.