Vedel, Søren1; Tay, Savas4; Johnston, Darius M4; Bruus, Henrik2; Quake, Stephen R4
1 Department of Micro- and Nanotechnology, Technical University of Denmark2 Department of Physics, Technical University of Denmark3 Biophysics and Fluids, Department of Physics, Technical University of Denmark4 Swiss Federal Institute of Technology
In multicellular organisms and complex ecosystems, cells migrate in a social context. Whereas this is essential for the basic processes of life, the influence of neighboring cells on the individual remains poorly understood. Previous work on isolated cells has observed a stereotypical migratory behavior characterized by short-time directional persistence with long-time random movement. We discovered a much richer dynamic in the social context, with significant variations in directionality, displacement, and speed, which are all modulated by local cell density. We developed a mathematical model based on the experimentally identified "cellular traffic rules" and basic physics that revealed that these emergent behaviors are caused by the interplay of single-cell properties and intercellular interactions, the latter being dominated by a pseudopod formation bias mediated by secreted chemicals and pseudopod collapse following collisions. The model demonstrates how aspects of complex biology can be explained by simple rules of physics and constitutes a rapid test bed for future studies of collective migration of individual cells.
National Academy of Sciences. Proceedings, 2013, Vol 110, Issue 1, p. 129-134