Fig 1: Reduced PAK2 activates the SAC and increases the incidence of aneuploidy.A Control and Pak2-KD oocytes were immunolabeled with anti-BubR1 antibody (green) and counterstained with PI to examine chromosomes (red). Representative confocal images of pre-MI and MI oocytes are shown. Arrowheads indicate scattered chromosomes in Pak2-KD oocytes (scale bar, 2.5 µm). B Quantification of BubR1 fluorescence intensity in control and Pak2-KD oocytes (19.3 ± 1.70%, n = 46, control; 70.7 ± 1.70%, n = 42, Pak2-KD). C Chromosome spreads of control and Pak2-KD MII oocytes (chromosomes were stained with Hoechst 33342 [blue]). Representative confocal images show euploid control oocytes and aneuploid Pak2-KD oocytes. Arrows indicate the premature separation of sister chromatids (scale bar, 2.5 µm). D Quantification of aneuploidy in control (n = 43) and Pak2-KD (n = 50) oocytes (10.3 ± 1.25%, n = 43, control; 39.0 ± 2.16%, n = 50, Pak2-KD). Graph shows the mean ± SD of the results obtained from three independent experiments. *Significantly different (p < 0.05).