Fig. 1. zyg-11, cul-2 and cyb-3 are required for progression through meiosis II. (A) Images from time-lapse sequences of embryos expressing GFP-HIS (see also Movies 1-7 at http://dev.biologists.org/supplemental/). Metaphase views are: polar (P), the spindle is viewed from the pole and five homologues (meiosis I) or sister chromatids (meiosis II) are observed in a circle around the sixth; lateral (L), the spindle is viewed from the side and up to three pairs of homologues (meiosis I) or sister chromatids (meiosis II) are observed; or intermediate (I), between the polar and lateral views. In this and other figures, embryos are oriented with polar bodies to the left and all panels of a kind are at the same magnification. Scale bar: 5 µm. (B) Timing of events in embryos from fertilization (t=0) until the end of meiosis II. Average duration of each stage, defined in Table 1, is indicated. Letters in the time-lines indicate the time at which the corresponding images in (A) are taken. Vertical white lines indicate the time at which GFP-PAR-2 first becomes enriched at the cell cortex in the vicinity of oocyte-derived chromosomes in zyg-11(RNAi) (n=4) or zyg-11(mn40) (n=3) embryos imaged starting at the end of meiosis I.