Cell division: a source of active stress in cellular monolayers

TL;DR

This paper demonstrates that cell division acts as a source of active stress, generating flow patterns and instabilities in cellular monolayers, and extends hydrodynamic models to incorporate division-induced activity.

Contribution

It introduces the concept of division-induced activity in active matter models and shows how it influences flow, defect density, and colony boundary dynamics.

Findings

Division generates extensile forces in cell assemblies.

Model reproduces flow fields observed in dividing MDCK cells.

Division-induced activity affects defect patterns and colony expansion.

Abstract

We introduce the notion of cell division-induced activity and show that the cell division generates extensile forces and drives dynamical patterns in cell assemblies. Extending the hydrodynamic models of lyotropic active nematics we describe turbulent-like velocity fields that are generated by the cell division in a confluent monolayer of cells. We show that the experimentally measured flow field of dividing Madin-Darby Canine Kidney (MDCK) cells is reproduced by our modeling approach. Division-induced activity acts together with intrinsic activity of the cells in extensile and contractile cell assemblies to change the flow and director patterns and the density of topological defects. Finally we model the evolution of the boundary of a cellular colony and compare the fingering instabilities induced by cell division to experimental observations on the expansion of MDCK cell cultures.