A minimal physical model captures the shapes of crawling cells

TL;DR

This paper introduces a minimal physical model of crawling cells using active polar fluid dynamics, successfully reproducing various cell shapes and motility behaviors observed experimentally, highlighting autonomous physical mechanisms in cell movement.

Contribution

The study presents a simplified active fluid model that captures diverse cell shapes and motility regimes, emphasizing physical mechanisms over regulatory control.

Findings

Model reproduces experimentally observed cell shapes.

Demonstrates autonomous physical mechanisms drive motility.

Shows variety of shapes and movement patterns.

Abstract

Cell motility in higher organisms (eukaryotes) is crucial to biological functions ranging from wound healing to immune response, and also implicated in diseases such as cancer. For cells crawling on hard surfaces, significant insights into motility have been gained from experiments replicating such motion in vitro. Such experiments show that crawling uses a combination of actin treadmilling (polymerization), which pushes the front of a cell forward, and myosin-induced stress (contractility), which retracts the rear. Here we present a simplified physical model of a crawling cell, consisting of a droplet of active polar fluid with contractility throughout, but treadmilling connected to a thin layer near the supporting wall. The model shows a variety of shapes and/or motility regimes, some closely resembling cases seen experimentally. Our work strongly supports the view that cellular motility exploits autonomous physical mechanisms whose operation does not need continuous regulatory effort.