Active fluctuations of cells reduce friction to enable fast and coherent collective migration

Collective cell migration is an emergent phenomenon, with long-range cell-cell communication influenced by various factors, including transmission of forces, viscoelasticity of individual cells, substrate interactions, and mechanotransduction. We investigate how alterations in cell-substrate dynamics, cell-substrate adhesion, and traction forces impact in-plane fluidity and temporal-spatial correlation of confluent monolayers comprising wild-type MDCK II cells or ZO1/2-depleted MDCK II cells (dKD). The combined data indicates that confluent dKD monolayers exhibit decreased in-plane fluidity compared to WT cells along with increased substrate adhesion, reduced traction forces, a more compact shape, diminished cell-cell interactions, and reduced cell-substrate height fluctuations. Depletion of basal actin and myosin further supports the notion that short-range cell-substrate interactions, particularly fluctuations driven by the basal actomyosin, significantly influence the migration speed of the monolayer on a larger length scale. Importantly, this in-plane fluidity proves to be highly compliant, requiring only a small portion of dynamic cells to maintain migration speed. ### Competing Interest Statement The authors have declared no competing interest.