Figure 3
Chromosome misalignment and incorrect kMT attachment in Zwint-1-knockdown oocytes.
(a) Oocytes in MetI (6 h after GVBD for Zwint-1-knockdown and 8 h after GVBD for control oocytes) were fixed and stained with anti-tubulin antibodies, ACA and DAPI. Scale bar, 10 μm. (b) Metaphase plate width was determined by measuring the axis distance between the two lines at the edges of the DNA. Data are mean ± SEM from three independent experiments with the indicated number of oocytes shown above the bars (*p < 0.0001). (c) Control or Zwint-1-knockdown oocytes expressing histone H2B-mCherry were visualized by time-lapse microscopy. Snapshot images from a representative movie are shown. The indicated number of oocytes has been analyzed in three independent experiments. Scale bar, 20 μm. Note that the PBE was accelerated and chromosomes were misaligned in Zwint-1-knockdown oocytes. (d) Oocytes in MetII stage were cultured with 200 μM monastrol for 2 h and chromosome spreads were performed. Arrows indicate single chromatids enlarged. Scale bar, 10 μm. Quantification of aneuploidy is shown in the right panel. Data are mean ± SEM from three independent experiments (*p = 0.0002). The number of oocytes analyzed is shown above the bars. (e) Oocytes were cold-treated and stained with anti-tubulin antibodies and ACA at 8 h after GVBD for control and 6 h after GVBD for Zwint-1 knockdown. The area outlined in the white line is enlarged in the right panel. The arrow head indicates an unattached kinetochore. Scale bar, 10 μm. The unattached kinetochores were quantified in the right panel. Data are mean ± SEM from three independent experiments. The number of oocytes analyzed is shown above the bars (*p = 0.0001).
