Time-lapse confocal microscopy of GFP-ECT-2, mCherry-PAR-2 in control one-cell stage C. elegans embryos. Time-lapse movies were acquired using FV3000 Confocal system, 60X 1.4 NA objective, with high-sensitivity cooled GaAsP detection unit (Olympus Corporation, Japan) at 1 frame every 20 seconds, played at 20 frames/sec. Note that the appearance of a single PAR-2 polarity axis is coincident with ECT-2 exclusion from the posterior cell cortex.