Species:

Strongylocentrotus purpuratus (purple urchin)

What’s in view:

Vegetal hemisphere at the eight-cell stage

What’s glowing:

Microtubules (blue) labeled by 3x-mCherry-Ensconsin, Active Rho (orange) labeled by GFP-Rhotekin

Frame rate:

12 sec/frame @ 15 fps = 180-fold time-lapse

Points of interest:

micromere formation; asymmetric cytokinesis

Optics:

BioRad Radiance laser scanning confocal; 40x oil lens; single optical section.

Filmed by:

George von Dassow, Bill Bement

More like this:

Here’s a larger version: 073008_SpRhoEns_02-lg.mov

Please see also the Supplemental Data page and our paper “Action at a distance during cytokinesis”.