Fig. 2. Cortical polarity in one-cell C. elegans embryos. (A-F) Illustrations of aspects (see key) of C. elegans embryos as they change from entry into the first cell cycle (left), to the completion of polarity establishment (right), a period of about eight minutes. The approximate timing of events relative to entry into the first cell cycle is shown in the upper bar. Cortical activity is indicated by the gray outline of the embryos; contractility is indicated by the cortical ingressions. The identity of the proteins or complexes depicted is indicated in the key. The acto-myosin network in C is indicated from a surface view of the embryo cortex; other proteins and centrosomes are shown in the embryo mid-plane. Embryo anterior is to the left. The complete kinetics of RhoGAP CYK-4 localization (E) have not been investigated and thus are not depicted following the initiation of polarization.