Fig. 4. GFP-ERGIC-53 tubule formation during rewarming from 16°C. GFP-ERGIC-53-expressing HeLa cells were incubated for 3 hours at 16°C, shifted to 37°C for 1 minute 53 seconds and imaged every 0.6 second (see supplementary material Movie 8). 0 second indicates the time at which imaging started. Extensive tubular structures appear from peripheral ERGIC spots and move with no preference in different directions. A single ERGIC structure can simultaneously extend tubules in opposite directions without being consumed (arrow). Several rounds of tubule emission from the same ERGIC spot do not consume it (arrowhead). Bar, 5 µm. Time, minutes.seconds.