Figure 7. Modeling analysis of the impact of myosin-dependent and myosin-independent cell shortening forces in the constriction domain on binary tissue response.

(a) The myosin-dependent, active lateral shortening forces and myosin-independent, passive lateral shortening forces function additively to mediate cell shortening and furrow invagination in the 2D vertex model. The active and passive lateral forces are given by $K_{L\_active}l$ and $K_{L\_passive}(l-l_0)$, respectively, where $l$ and $l_0$ are the current and the resting length of the lateral edge, respectively. Green shaded region represents the conditions where the model generates normal final furrow morphology. (b) When $K_{L\_passive}=20$, changing $K_{L\_active}$ has little impact on the binary response of the model to stimulation. (c) When $K_{L\_active}=2$, changing $K_{L\_passive}$ does not affect the binary tissue response per se but influences the final morphology after stimulation.