Cell Mechanics at the Rear Act To Steer the Direction of Cell Migration

Abstract

1 These authors contributed equally to this work. Highlights• Fish keratocytes can migrate with persistent angular velocity, straight or in circles.• Asymmetry in protrusion at the leading edge is not sufficient to generate persistent turning.• Asymmetries in myosin II contraction, actin flow and adhesion at the cell rear cause turns.• Our new computational model of migration predicts observed cell trajectories.

Modeling cell turning by mechanics at the cell rear

“…Yet, once the externally imposed bias in myosin concentration is removed, myosin re-distributes around the cell, the cytoskeletal symmetry is restored, and the cell starts to move straight. This matched experimental findings from asymmetric exposure to the myosin activating small molecule calyculin ( Figure 6A in [12]). The results indicate that the positive feedback between the kinematics of turning and myosin distribution are sufficient for transient but not persistent turning.…”

“…2C) that results in peaks in the angular speed distribution, which correspond to persistent turning with rates on the order of ~ 1 degree per second, as observed [12]. Simulations produce trajectories illustrated in Figure 3, which agrees with experimental results [12].…”

“…The steady asymmetric cell shape and turning with a constant-radius trajectory evolved from this initial condition, with the shape and patterns of myosin distribution, actin flow and traction forces ( Fig. 2A) mimicking those observed in the experiment [12].…”

“…We observed that the myosin distribution in both cases was biased toward the fast side of the cell due to the kinematic actin flow, with only slight insignificant differences in myosin distributions between these two cases. However, only an asymmetric adhesion distribution could replicate experimental measurements of traction forces [12].…”

“…1B), chosen to approximate an experimentally measured turning cell shape ( Fig. 3f in [11] and [12]). Similar to the observed turning cells, there is a lower aspect ratio on the slower side and a higher aspect ratio on the faster side, i.e.…”