FIG. 8.

A. Collective guidance requires, through some mechanism, a comparison between cell states to create an estimate of gradient direction (blue arrow). These estimates are biased if each cell’s response to the concentration measurement is highly variable. I show schematically how this estimate is biased toward a cell that has an anomalously strong response (cell with red X). B. When cell-to-cell variability is large, the cluster fluidity can control the cluster accuracy (chemotactic index); here the fluidity is regulated by cell-cell adhesion, taking the cluster from fluid to solid. Also shown are corresponding fluid and solid clusters, with colors indicating degree of signaling strength. This panel is adapted from [92], and simulation details can be found there.