Movie 4

Finite Element simulations of progenitor cell sorting using relative interfacial tension distributions determined in vitro and in vivo.
The movie shows two Finite Element (FE) simulations with identical starting configuration of heterotypic aggregates composed of ectoderm (red) and mesoderm (green) cells surrounded by culture medium (blue). In these finite element-based simulations, the cells in the heterotypic aggregate shown on the left side of the movie were assigned the relative tensions measured by CellFIT-3D in in vitro aggregates under standard culture conditions (γ_e-e = 1.00, γ_m-m = 1.31, γ_e-m = 1.66, γ_e-cm = 2.65, γ_m-cm = 1.20; as in Fig. 1C). The model cells (ectoderm cells are shown in red and mesoderm cells in green) displayed a clear sorting behaviour similar to their experimental counterparts. If instead the interfaces are assigned the tensions that CellFIT-3D shows to act in in vivo (γ_e-e = 1.00, γ_m-m = 1.28, γ_e-m = 1.25, γ_e-cm = 0.78, γ_m-cm = 0.63; Fig. 1J), cells do not sort (right part of the movie). The simulations of the modelled cell aggregates have the same initial configuration and are time synchronized (5000 iterations). Frame rate, ~ 30 fps.