Figure 3.

Force field of three chain type microplasmodia. (a) Initially, the first one presents two main circular contraction units (surrounded by dotted circles) where force vectors converge centripetally. (b) Later, it expands a pseudopod on the right and a new centripetal contraction unit is created (blue circle). (c) Time series of cell area and force changes in zones surrounded by dotted circles in (a,b). The middle zone (green circle) exhibits force oscillations in phase opposition with area. The interval between peaks of area (vertical dotted lines) is T = 1.15 min. (d–f) The second microplasmodium, not moving, has two synchronized contractile units in phase opposition with area oscillations (T = 2.1 min). (g) The third one has a dumbbell shape. Forces are not transmitted to substratum under the long central connecting tube (arrowhead). (h) Later, the bottom-left contractile unit progressively shrinks and the other one grows. (i) Forces in the two contractions units mostly oscillate in counter-phase.