甘氨酸提高水貂卵母细胞玻璃化冷冻保存效率的关键机制

打开文本图片集

中图分类号：S814 文献标志码：A 文章编号：0366-6964（2025）07-3265-13

Abstract： This study aimed to investigate the effects of glycine，a small-molecule permeant that optimizes cellular volume regulation， on improving the cryopreservation efficiency of mink germinal vesicle （GV） stage oocytes during vitrification， thawing，and subsequent in vitro maturation （IVM）. Ovaries were collected from sexually mature female minks （1-3 years old） during the breeding season （February-March）.The collected oocytes were randomly divided into 3 groups： control （fresh oocytes），vitrified without glycine （vitrified group），and vitrified with 5mmol⋅L-1 glycine（vitrified + Gly group），each group contained at least 2O oocytes，each experiment was repeated at least 3 times. Glycine of 5mmol⋅L-1 was supplemented during vitrification， thawing，and IVM. Post-thaw assessments included survival rate， nuclear maturation rate， mitochondrial integrity， cortical granule distribution， reactive oxygen species （ROS） levels，apoptosis，and histone modifications （ H3K9 methylation）. Quantitative PCR and immunofluorescence were employed to analyze apoptosis-related genes （CASP3， BAX ，BCL-2） and DNA methyltransferase 1 （DNMT1） expression. Glycine supplementation during vitrification and IVM significantly enhanced the biological function of cryopreserved oocytes. Compared to the non-glycine vitrified group， glycine-treated oocytes exhibited higher survival rate（ ⋅P<0.05 ）and nuclear maturation rates （ P<0.05 .Mitochondrial damage and cortical granule mislocalization were reduced （ P<0.05 ），while ROS levels decreased（ P<0.05） ： Apoptosis rates declined with downregulated CASP3 and BAX expression （ P<0.05 ）andan elevated BCL-2/BAX ratio（ P<0. 05 ）.Additionally，glycine improved DNMT1 transcription （ P<0.05 ）and H3K9 methylation levels （ P<0.05 ）in MII oocytes post-vitrification. In summary，oocytes osmosis damage caused by addition or removal of cryoprotectants during vitrification can regulate oocyte volume homeostasis by addition of glycine，thereby improving the developmental ability of vitrification mink oocytes.

Keywords：vitrification；mink oocytes；glycine；volume regulation ∗ Corresponding author：XU Baozeng，E-mail： xubaozeng@caas.cn

水貂作为我国重要的毛皮经济兽，是毛皮动物养殖行业的支柱型产业之一。（剩余21853字）