Improving the realism of the cellular Potts model in simulations of biological cells

Ouchi, Noriyuki; Glazier, J. A.*; Rieu, J.-P*; Upadhyaya, A.*; Sawada, Yasuji*

Because the extended large-Q Potts model captures effectively the global features of tissue rearrangement experiments, including cell sorting and tissue engulfment, it has become a common technique for cell level simulation of tissues. It agrees qualitatively with experiments. However, standard simulations using positive surface energies fail to describe correctly the dynamics of single cells moving within an aggregate. In particular, the hierarchy of diffusion constants is reversed compared to experiments. The standard model also suffers from numerical instabilities. In this letter, we show how to modify the Hamiltonian using negative surface energies and a spin flip energy threshold to improve the correspondence to experiments. We also investigate diffusion constant dependence on model parameters.