Comet assay
As described in our recent publication (Dong et al., 2022), after carefully filling 0.5% LMP (Low-melting-point) agarose flowing at liquid state above the normal melting point agarose, oocytes were transferred quickly into the LMP layer and then placed at 4°C for LMP liquid solidification, followed by soaking in lysing solution at 4°C for 1h, and washing with distilled water for 10 min, then transfer into alkaline buffer for 20 min on ice before electrophoresis at 25V for 20 min. Finally, the oocytes were stained with EB (20μg/ml) for 15 min and then examined with a fluorescence microscope (Leica, Germany). CASP software was used to analyze the comet tail length and comet tail DNA.