Zhou Guang-Bin, Li Ning
State Key Laboratory for Agrobiotechnology, China Agricultural University, Haidian District, Beijing 100193, People's Republic of China.
Mol Hum Reprod. 2009 May;15(5):279-85. doi: 10.1093/molehr/gap016. Epub 2009 Feb 27.
Successful cryopreservation of porcine gametes and embryos has been very challenging due to their sensitivity to cryoinjuries. Although considerable improvements have been achieved in the vitrification of porcine embryos, there has been no offspring born from the vitrified oocytes in this species. Porcine oocytes characteristically contain large amounts of cytoplasmic lipids that are major obstacles limiting efficient cryopreservation. These droplets together with structures such as mitochondria, membranes, cortical granules and basic components of the spindle and cytoskeleton (microtubules and microfilaments) often incur serious damage during cooling and warming. According to recent reports, the proper combinations of permeable and non-permeable cryoprotectants and vitrification with high cooling and warming rates may increase the survival of porcine oocytes. The cryotolerance of porcine oocytes may also be enhanced by removal of the chilling-sensitive lipid droplets, supplementation of cytoskeleton relaxants in vitrification solutions, or high hydrostatic pressure pretreatment of oocytes before cryopreservation. The improvement in cryopreservation methodology for porcine oocytes will no doubt augment other technologies such as pig cloning and the establishment of a gene bank for transgenic pigs.
由于猪的配子和胚胎对冷冻损伤敏感，成功冷冻保存它们极具挑战性。尽管猪胚胎玻璃化冷冻技术已取得显著进展，但该物种中通过玻璃化冷冻的卵母细胞尚未有后代出生。猪卵母细胞的特征是含有大量细胞质脂质，这些脂质是限制有效冷冻保存的主要障碍。这些脂滴以及线粒体、细胞膜、皮质颗粒和纺锤体及细胞骨架（微管和微丝）的基本成分等结构，在冷却和升温过程中常常会受到严重损伤。根据最近的报道，渗透型和非渗透型冷冻保护剂的适当组合以及采用高冷却和升温速率的玻璃化冷冻方法，可能会提高猪卵母细胞的存活率。去除对低温敏感的脂滴、在玻璃化溶液中添加细胞骨架松弛剂或在冷冻保存前对卵母细胞进行高静水压预处理，也可能增强猪卵母细胞的耐冻性。猪卵母细胞冷冻保存方法的改进无疑将促进其他技术的发展，如猪克隆以及建立转基因猪基因库。
