Figure 2. Treatment with NAC delays the changes in spindle anomalies of post-ovulatory oocyte aging in vitro. (A) Different morphological structures of spindles appeared in fresh and aged oocytes. Meiotic spindles in oocytes were stained with α-tubulin (green) and chromosomes were stained with Hoechst 33342 (blue). (B) Percentages of abnormal spindles in oocytes. Oocytes containing normal spindles and those with abnormal spindles were counted to calculate the percentage of abnormal spindles. NC, oocytes treated without NAC. 0.6mM, oocytes treated with 0.6mM NAC. Data are expressed as mean ± SEM of at least 3 independent experiments, and 6 superovulated mice were killed to obtain a minimum of 40 oocytes for each experiment. Data are expressed as mean ± SEM. Star represents mean difference, 0.01< p < 0.05. (C) Control or NAC treated oocytes, which were microinjected with MAP4-eGFP mRNA and H2B-mCherry mRNA, and visualized by time-lapse live-cell imaging. The spindles are marked in green, and chromosomes are marked in red. Independent replicates were conducted with a minimum of 20 oocytes.