Migrating cells leave behind ACA-containing vesicles. (A) Sequential fluorescent maximum intensity projections of an ACA-YFP/aca⁻ cell leaving tracks containing ACA-YFP. Arrows indicate tracks. Also see Videos 7 and 8. (B) Fluorescent maximum intensity projections of ACA-YFP/aca⁻ cells leaving tracks containing ACA-YFP. (C) Graph depicting the fluorescence intensity of tracks/cell in ACA-YFP/aca⁻ cells treated with 60 μM Noco or 200 μM CHX for 1 h and migrating to a micropipette filled with 10 μM cAMP (see Materials and Methods and Fig. S3 for details). Data represent means ± SEM of four independent experiments totaling ∼165 cells.