Description

Microtubules in sand dollar embryo expressing three tandem GFPs fused to the ensconsin microtubule-binding domain (EMTB-3G; Faire et al., 1999). Eight-cell sand dollar embryo; single microtubules grow as far as the cell surface in all directions (equatorially in the 01:56 frame, tropically in the 01:08 frame, and toward the pole in the 03:32 frame). Astral microtubules reach the polar cortex most densely in anaphase (08:48) but also reach the equator before furrowing (frame 10:48). 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, which is tolerated well. Video corresponds to Fig 1C and third segment in Video 1 from J Cell Biol. 2009 Dec 14;187(6):831-45.