Fig 4. mAb 6H11 injection prevents Megator redistribution from the nuclear envelope during mitosis.

(A) Diagram of the dynamics of Megator localization (in green) during mitosis in unperturbed embryos based on the results of Yao et al. (Fig 6 in Yao et al. [5]). (B) Confocal time-lapse sequence of a mAb 6H11 injected syncytial embryo expressing Megator-YFP (in green) and Tubulin-mCherry (in red). The antibody was injected at interphase and the image sequence starts at metaphase of the first cell cycle, which progressed normally, while the second cycle is arrested prior to NEB. The last image was obtained approximately 35 min after the first cell cycle was completed. The chromosomes have condensed (dark regions indicated by white arrows) and Megator-YFP is still present on the NE at a time when it normally would have relocalized to the spindle matrix. Time is indicated in minutes and seconds. (C) Comparison of Megator dynamics in colchicine- and mAb 6H11-arrested embryos. In wild-type, Megator is localized to the nuclear interior and the NE at interphase and relocalizes to the spindle matrix at prophase. In colchicine-arrested embryos Megator dynamics is as in wild-type embryos (Fig 5E in Yao et al. [5]); however, in mAb 6H11-arrested embryos Megator remains at the nuclear rim, the spindle matrix does not form, and NEB does not occur.