Fig. 3.

MPS simulation of cytoplasmic flow in the C. elegans one-cell stage embryo (∼5–7 min before pronuclear meeting). (A) A snapshot of the velocity distribution in the equatorial section of the C. elegans embryo cell during the simulation (cytoplasm particles only). The cell shape was a cylinder with a hemisphere at each end. Red and blue particles indicate the particles moved into the posterior and anterior directions, respectively, in the simulation. The velocities of the green particles are near zero. (B) The velocity distribution along the AP axis in vivo reconstructed with MPS simulation. The velocity components along the AP axis (//AP) of the cortical flow and cytoplasmic flow were plotted against the distance from the posterior pole along the AP axis (x-axis). Positive and negative values correspond to posterior-directed and anterior-directed velocities, respectively. Boxes show the experimental records (gray: cortical flow, white: cytoplasmic flow). The simulation data are shown with lines (gray: cortical flow, black: cytoplasmic flow). (C) The velocity distribution along the axis perpendicular to the AP axis reconstructed with MPS simulation. The velocity components along the AP axis (//AP) in the posterior region and the anterior region were compared. Positive and negative values correspond to posterior-directed and anterior-directed velocities, respectively. Boxes show the experimental records (gray: anterior region, white: posterior region). The simulation data are shown with lines (gray: anterior region, black: posterior region).