MTOC positioning and MT dynamics determine the path of migration. (a) DC migrating within a pillar array. Upper panel shows EB3-mCherry (EB3-mCh.) expression profile. Lower panel ooutlines dynamic cell shape changes. Scale bar, 10 µm. (b) Time projection of image sequence shown in panel a. Left panel indicates MTOC position over time. Right panel outlines the formation and retraction of multiple explorative protrusions over time. (c) DC migration in Y-shaped decision channels. Left panel outlines the channel geometry of Y-shaped devices. Upper panel shows the EB3-mCherry expression profile. Lower panel shows higher magnification at the decision point. Red arrowheads indicate MTOC position before and after the decision, respectively. Scale bar, 10 µm. (d) Mean number of EB3 comets in winner versus loser protrusions before and after the decision of n = 7 cells. Mean ± SD. (e) Mean number of EB3 comets normalized (Norm.) to the maximum number of comets in each protrusion over time of n = 7 cells ± SD. (f) Mean EB3 comet reach into protrusions over time of n = 7 cells ± SD. (g) EB3-mCherry–expressing DC migrating in a hexagonal channel array. Red box indicates area magnified in the lower panel. Scale bar, 10 µm. See also Video 1.