In  I developed a fluid dynamical model for cell and tissue movements. The cells were represented by polygons in a numerical algorithm. Forces causing movements acted along cell membranes (polygon edges) and arose from adhesions at cell interfaces and cell-substrate contacts. The model generated motion in the cell configuration by maximizing the rate of free energy decrease, subject to an energy dissipation constraint. The form of this constraint was suggested by fluid mechanics, resulting in aggregate motion which resembled motion of a slow, viscous fluid driven by surface tension forces. The model was used successfully to simulate cell reaggregation and sorting experiments  and to model neuralation in amphibian embryos, a process in which a circular monolayer of cells changes to a keyhole shape .
The exact nature of mechanisms responsible for cell movements in embryos is not known. This work showed that a simple mechanism could be responsible for generating some of the observed patterns of cell movements and shape changes in embryos. In this study, the number of binding sites on the cell membrane determines the strength of cell adhesion to neighboring cells and to the substrate. Once the distribution of binding sites is specified, the motion is determined by physical principles that are not specific to living matter.
Last updated: September, 1998
Copyright © 1998, Deborah Sulsky