Differential tissue growth and cell adhesion alone drive early tooth morphogenesis: An ex vivo and in silico study
Fig 9
Epithelium-mesenchyme separation experiments.
A, Pictures of the same E14.5 tooth germ before immersion in dispase with the four 2D configuration of landmarks used in Geometric Morphometrics analyses (left), 14 mins after (middle) and 40 minutes after (right). Landmark configurations were collected for each of the 120 time frames which compose the total duration of the separation experiment. B, Depiction of mechanical stresses in the in silico separation assay before separation (left) and C, after the tissues have reached mechanical equilibrium (right). Colour rods indicate direction and intensity (yellow for tension, blue for compression) at a certain cell-cell contact (as in Fig 7). Growth and adhesion parameters used: sepi = 0.055, ssup = 0.033, smes = 0.245, bee = 5.0, bes = 5.0, bem = 5.0, bss = 5.0, bmm = 5.0. D, PCA of tooth germ variation during separation from experimental data from three different tooth germs (red, yellow and blue dots, n = 120 each), and from the simulation data shown in B (black dots, n = 120). The arrows point the flow of time for each dataset. The outline drawings of tooth germs show the patterns of shape changes associated with each PC from the overall average shape (solid grey outline with grey background and open circles) for different PC scores (solid black outline and solid black circles). Note that the outline drawings are depicted for an easier visualisation.