FIGURE 1.

Cortical flow-based migration in confinement. (A) Illustration of non-specific friction mediated cell motion in a cylindrical microchannel Bergert et al. (2015). Rearward cortical flow is driven by a gradient in contractility ζ(x), and momentum is thought to be transferred to the surroundings by transient adhesion and lubrication forces. The channel is filled with fluid, which hydraulically resists cell migration. (B) Migration of talin knock-out leukocyte in a wavy channel Reversat et al. (2020). Substrate topography forces the cortical flow to be curvilinear, creating bending stresses and, as a result, an asymmetric profile in normally-oriented substrate forces. This gives rise to a net propulsion force in the direction opposite to that of the cortical flow.