(A) Confocal image sequence of Polo-GFP during the cell cycle in an untreated embryo. Time is indicated in minutes and seconds. (B) Diagram of Polo (in green) dynamics during mitosis in unperturbed embryos. (C) Comparison of Polo localization after cell cycle arrest with colchicine- and mAb 6H11-injections, respectively. In wild-type, Polo is present at centrosomes but not in the nuclear interior at interphase; however, it accumulates during pro- and prometaphase and transiently relocalizes to the nuclear rim and the kinetochores. After colchicine-arrest Polo localizes to the spindle matrix, the nuclear rim, and kinetochores as in wild-type preparations. However, in mAb 6H11 arrested embryos Polo does not accumulate in the nucleus and is present only at centrosomes. (D) Confocal image of polo-GFP from an image sequence from a colchicine-arrested embryo showing Polo-GFP enrichment at the nuclear rim and at the kinetochores. (E) Confocal image of Polo-GFP from the end of an image sequence of a mAb 6H11-arrested embryo where Polo-GFP is only present at the centrosomes.