Figure 2. Rab6a depletion causes spindle disorganization and chromosome misalignment in oocyte meiosis.

Control and Rab6a-siRNA oocytes were stained with α-tubulin antibody to visualize the spindle (green) and counterstained with PI to visualize chromosomes (red). (A) Control metaphase oocytes (a) present a typical barrel-shape spindle and well-aligned chromosomes on the metaphase plate; (b) in anaphase oocytes (b) chromosomes move evenly away from the equator toward opposite poles, and homologous chromosomes are accurately segregated in telophase oocytes (c). (B) Spindle defects (arrows) and chromosomes misalignment (arrowheads) were frequently observed in Rab6a-depleted oocytes. Representative confocal sections are shown. Scale bar, 25 μm. (C) Quantification of control and Rab6a-siRNA oocytes with chromosome misalignment. (D) Quantification of control and Rab6a-siRNA oocytes with spindle defects. Data are expressed as mean percentage ± SD from three independent experiments in which at least 100 oocytes were analyzed. *p < 0.05 vs. controls.