Time-lapse DIC microscopy of wild-type (N2) one-cell stage of C. elegans embryos. In these and other movies, anterior is on the left, and the embryos are approximately 50 μm long. Time-lapse movies were acquired using Differential Interference Contrast (DIC) microscopy (Axioskop, Carl Zeiss Inc.) at 1 frame every 5 seconds, and played at 20 frames/sec.