Figure 4. Effects of Nrf2 knockdown on spindle structure, chromosome alignment, Cyclin B1 and CDK1 levels of mouse oocytes. (A) Control and Nrf2-KD oocytes were collected and stained for visualizing spindle (green) and chromosomes (blue). Scale bar, 20 μm. (B) Quantiﬁcation of control and Nrf2-KD oocytes with spindle defects or chromosome misalignment. (C) The relative mRNA level of Cyclin B1 and CDK1 were determined by RT-qPCR in control and Nrf2-siRNA injected oocytes. mRNA levels in control oocytes were set to 1. (D) Western blot analysis showing the reduced expression of Cyclin B1 after Nrf2 siRNA injection. (E) Decreased CDK1 protein levels in Nrf2-KD oocytes. Data are expressed as the mean ± SD, *P<0.05 vs. control.