title: A minimal physical model captures the shapes of crawling cells.
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.
authors.affiliation: SUPA, School of Physics and Astronomy, University of Edinburgh, JCMB Kings Buildings, Mayfield Road, Edinburgh EH9 3JZ, UK.
authors.forename: E
authors.initials: E
authors.lastname: Tjhung
authors.affiliation: SUPA, School of Physics and Astronomy, University of Edinburgh, JCMB Kings Buildings, Mayfield Road, Edinburgh EH9 3JZ, UK.
authors.forename: A
authors.initials: A
authors.lastname: Tiribocchi
authors.affiliation: SUPA, School of Physics and Astronomy, University of Edinburgh, JCMB Kings Buildings, Mayfield Road, Edinburgh EH9 3JZ, UK.
authors.forename: D
authors.initials: D
authors.lastname: Marenduzzo
authors.affiliation: SUPA, School of Physics and Astronomy, University of Edinburgh, JCMB Kings Buildings, Mayfield Road, Edinburgh EH9 3JZ, UK.
authors.forename: M E
authors.initials: ME
authors.lastname: Cates
mesh_terms: D000199:Actins / Q000737:chemistry; D000465:Algorithms; D000818:Animals; D001703:Biophysics; D002465:Cell Movement; D048430:Cell Shape; D003198:Computer Simulation; D003599:Cytoskeleton / Q000378:metabolism; D004058:Diffusion; D006801:Humans; D021621:Imaging, Three-Dimensional; D008954:Models, Biological; D009068:Movement; D009218:Myosins / Q000737:chemistry; D009369:Neoplasms / Q000378:metabolism; D010587:Phagocytosis; D013816:Thermodynamics
chemical_list: D000199:Actins; D009218:Myosins