Viscoelastic cell model of sorting in the dictyostelium discoideum slug.

Cell sorting and differential motion are key processes in the life cycle of Dictyostelium discoideum (Dd) and many other organisms. Here we develop a mathematical model and investigate the processes with computer simulations. The slug stage of Dd is modeled with ellipsoidal cells of two types which have viscoelastic properties. Using the force-based model we find that when the two cell types have different strengths of motive forces and or different degrees of directionality one cell type sorts to the front of the slug. These findings are consistent with previously published results using a different model formation. When one cell type is more directed than the other it will consistently sort to the front of the slug. Likewise, but less efficiently, when one cell type exerts greater motive forces than the other it will sort to the front of the slug. The most efficient and robust cell sorting due to differential motion is when both methods are employed.