Figure 2. Intracellular particle motion in an acanthamoeba and its relation to locomotion.

(A) Phase contrast image of an A. castellanii trophozoite crawling on a surface. Scalebar: 10 μm. The arrow indicates the direction of acanthamoeba locomotion. (B) Particle trajectories tracked inside the acanthamoeba shown in A. Most tracks follow the direction of movement of the acanthamoeba centroid (bold red line). However, not all particles obey this trend. (C) Particle trajectories x_I(t), y_I(t) of intracellular particles relative to the position of the acanthamoeba centroid. No significant directionality of particle motion can be observed.