title: Multicellular density fluctuations in epithelial monolayers.
abstract: Changes in cell size often accompany multicellular motion in tissue, and cell number density is known to strongly influence collective migration in monolayers. Density fluctuations in other forms of active matter have been explored extensively, but not the potential role of density fluctuations in collective cell migration. Here we investigate collective motion in cell monolayers, focusing on the divergent component of the migration velocity field to probe density fluctuations. We find spatial patterns of diverging and converging cell groups throughout the monolayers, which oscillate in time with a period of approximately 3-4 h. Simultaneous fluorescence measurements of a cytosol dye within the cells show that fluid passes between groups of cells, facilitating these oscillations in cell density. Our findings reveal that cell-cell interactions in monolayers may be mediated by intercellular fluid flow.
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Zehnder
authors.affiliation: Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: Marina K
authors.initials: MK
authors.lastname: Wiatt
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Uruena
authors.affiliation: Department of Mechanical Science and Engineering, University of Illinois, Champaign-Urbana, Illinois 61801, USA.
authors.forename: Alison C
authors.initials: AC
authors.lastname: Dunn
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: W Gregory
authors.initials: WG
authors.lastname: Sawyer
authors.affiliation: Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611, USA.|J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611, USA.|Institute for Cell Engineering and Regenerative Medicine, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Angelini
mesh_terms: D000818:Animals; D002229:Carbenoxolone / Q000494:pharmacology; D002452:Cell Count; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D048429:Cell Size / Q000187:drug effects; D004285:Dogs; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D005456:Fluorescent Dyes; D017629:Gap Junctions / Q000187:drug effects / Q000378:metabolism; D061985:Madin Darby Canine Kidney Cells; D061848:Optical Imaging; D010507:Periodicity; D011312:Pressure
chemical_list: D005456:Fluorescent Dyes; D002229:Carbenoxolone