Testing the outcomes of simulations with or without any gradient of activity. (A) Squared velocities of actin-positive vesicles as a function of the distance to the oocyte center during the centering phase. One red dot corresponds to the averaged square velocities of vesicles in the given distance bin in one simulation, taken between 30 and 60 min of simulation only (simulations done as in Fig. 1). The black dots correspond to the experimental data from Almonacid et al. (2015) presented in Fig. 1 B, with the black line representing the fit extracted from these experimental data. (B) Time frames from one 3D simulation of an absence of gradient of persistence of actin-positive vesicles. The nucleus is not centered in these conditions. The nucleus is in blue, and the actin-positive vesicles are in red; the oocyte cytoplasm appears in gray. (C) Evolution of the distance between the nucleus centroid to the center of the oocyte as a function of time for 15 different simulations in the absence of a persistence gradient. Light blue curves correspond to individual simulations, while the dark blue curve corresponds to the mean curve for all simulations. (D) Squared velocity of actin-positive vesicles as a function of the distance to the oocyte center from simulations of a lack of gradient or from experimental data during the centering phase. The squared velocities of actin-positive vesicles obtained from simulations are in red, while the experimental data are in black. (E) Outcome from the two types of simulations on the final distribution of actin-positive vesicles. The density of actin-positive vesicles is presented as a heat map reflecting the number of vesicles per square unit during 1,000 min for the two types of simulations (with or without a gradient of persistence). To build the heat map, we aligned the simulations so that the nucleus is always on the right along the x-axis. One square unit corresponds to a square of 2.3 × 2.3 µm2 in size. Left panel: Persistence gradient; right panel: without the gradient.
