Extended Data Figure 6. Cell proliferation is required for tissue growth, symmetry breaking and fingering.

a, Simulation and Experimental results for the distribution of proliferating cells across spheroids in elastic (upper row) and viscoelastic gels (lower row): left, simulation example of the daughter cells (cyan) and the cells in the tissue spheroid (yellow elastic and cyan viscoelastic); center, representative examples of experimental spheroids showing EdU positive cells (cyan) and cell nuclei (Hoechst, magenta) for spheroids; right, colormaps showing the local percentage of Edu positive cells across the spheroid. b-c, Experimental (b) and simulation results (c) showing the density proliferating cells depending of distance from the spheroid edge. n=3,4 spheroids per condition. Error bars are s.e.m. All scale bars are 200 μm. d, The normalized stress energy estimated from the simulations depending on the distance from the spheroid edge. The dimensionless parameter in the model for stiff elastic $\left(A=\frac{{\tau }_{\mathrm{a}}}{{\tau }_{\mathrm{m}}}=0.4,\mu =\frac{{\mu }_{\mathrm{t}}}{{\mu }_{\mathrm{m}}}=\right.\left.0.002,j=\frac{{\tau }_{\mathrm{g}}}{{\tau }_{\mathrm{t}}}=0.05\right)$ and stiff viscoelastic $\left(A=\frac{{\tau }_{\mathrm{a}}}{{\tau }_{\mathrm{m}}}=400,\mu =\frac{{\mu }_{\mathrm{t}}}{{\mu }_{\mathrm{m}}}=2,j=\frac{{\tau }_{\mathrm{g}}}{{\tau }_{\mathrm{t}}}=0.22\right)$ matrices.