Video 4.
A cell moving in pure bleb mode under 0.7% agarose. An aggregation-competent Ax2 cell, expressing ABD-GFP as a reporter for F-actin, chemotaxing to cyclic-AMP under 0.7% agarose. When blebs detach from the cortex, they leave behind an F-actin scar, which gradually dissipates and sometimes moves in a retrograde direction; meanwhile, the bleb membrane becomes repopulated with F-actin in as little as one second. Left, DIC; right, ABD-GFP. Movie taken by DIC and laser-scanning confocal microscopy (model LSM 710; Carl Zeiss) at 2 frames per second.