One cell within a 16-cell sand dollar embryo expressing three tandem GFPs fused to the ensconsin microtubule-binding domain (EMTB-3G; Faire et al., 1999). The embryo was treated with 25 µM trichostatin A (TSA), an inhibitor of HDAC6 (a tubulin deacetylase) that selectively disrupts dynamic microtubules in mammalian cells 10 min before time 00:00. Although the aster regrows slightly, the cortex is ∼20 µm away from the nearest spindle microtubule ends; nevertheless, cytokinesis completes accurately. Sand dollar embryos were imaged with a laser scanning confocal microscope (Radiance 2000; Bio-Rad Laboratories) mounted on a compound microscope (E800; Nikon) using a 40× 1.3 NA Plan-Fluor oil lens. Room temperature was maintained at 14–17°C. Video correspond to Fig 4C and second segment of Video 4 in J Cell Biol. 2009 Dec 14;187(6):831-45.