Figure 1.

Illustration of spherical vesicles moving through the cytoplasm (dragged by molecular motors not shown). The illustration is roughly to scale with vesicle diameters 1 µm, height of the cytoplasm 10 µm and thickness of actin bundles 100 nm. The shaded tonoplast membrane separates cytoplasm and vacuole, which extends beyond the figure. In the simulations, the motors and the membrane are not modelled explicitly. (Online version in colour.)