Analysis of barotactic and chemotactic guidance cues on directional decision-making of Dictyostelium discoideum cells in confined environments

Significance Cells confined in complex environments use a combination of chemical and mechanical cues for robust pathfinding and effective migration. Analysis of directional “decision-making” of Dictyostelium discoideum cells migrating within microchannels harboring asymmetric bifurcations shows that unlike neutrophils and immature dendritic cells Dictyostelium cells use chemical rather than barotactic guidance cues. Cells in steeper adenosine 3′,5′-cyclic monophosphate gradients migrating at higher speeds split their leading edges more readily when confronted with a bifurcation in the channel. The point at which one of the competing pseudopods starts to retract appears to be dependent on a relative force imbalance between two competing pseudopods, showing that cellular mechanics plays a major role in leading-edge dynamics, including front splitting, polarization, and retraction in D. discoideum .