Figure 9

3D CPM simulations of single cells and tissues, within the four qualitatively different regions.(A) Single cell dynamics. All simulations used a 12th level neighbourhood (\(\xi =\frac {169}{4}\pi \approx 132.73\)) and V=5,000 (R _v =10.6); S=500 (\(S_{_{\mathit {CPM}}}=66,366\)); λ _v =50; λ _s =25 (\(\lambda _{s_{\,\mathit {CPM}}}=0.001419\)); and T=10,000. The J-value was modified to set τ: In region I, J=−55,000 (\(J_{_{\mathit {CPM}}}=-414\)); in region II, J=20,000 (\(J_{_{\mathit {CPM}}}=150\)); in region III, J=1,000,000 (\(J_{_{\mathit {CPM}}}=7,533\)); and in region IV, J=1,400,000 (\(J_{_{\mathit {CPM}}}=10,547\)). Initial radii are: region I and II, r=1; region III, top, r=4; region III, bottom, r=5; region IV, r=30. (B) Tissue dynamics. Shown are 13 individual cells located within a larger aggregate of cells (C). All parameters are the same as in (A), except for the J-values to set τ to be within the right zones (since the zone boundaries are different for spherical and rhombic dodecahedronal cell shapes). Note that \(J_{_{\mathit {CPM}}}=J_{C,M}=2J_{C,C}\), capturing the fact that in the CPM formalism the contribution by J to the interfacial tension along cell-cell boundaries — but not cell-medium boundaries — is shared between neighbouring cells. In region I, J=−65,000 (\(J_{_{\mathit {CPM}}}=-489\)); in region II, J=20,000 (\(J_{_{\mathit {CPM}}}=150\)); in region III, J=900,000 (\(J_{_{\mathit {CPM}}}=6,780\)); and in region IV, J=1,400,000 (\(J_{_{\mathit {CPM}}}=10,547\)). Initial radii are: region I and II, r=5; region III, top, r=3; region III, bottom, r=5; region IV, r=20.