家畜卵母细胞和胚胎去脂方法研究进展

Advances in Oocyte and Embryo Defatting Methods for Domestic Animals

卵母细胞和胚胎冷冻技术可与超数排卵和胚胎移植等繁殖技术相结合,打破生理、地区和时间对母畜繁殖潜力的限制,对国际种源流通、优良家畜扩繁和濒危动物种质资源保存具有重要意义。然而,卵母细胞和胚胎中丰富的脂质在降温过程中容易引起膜结构损伤、内质网和线粒体损伤、脂质过氧化,降低其解冻后发育能力,这极大地限制了冷冻卵母细胞和胚胎的应用。众多研究表明,在冷冻前降低卵母细胞和胚胎的脂质含量有利于提高其解冻后的存活率、囊胚率和妊娠率。目前,常用的降脂方法包括3种,即离心极化脂滴后通过显微操作去除脂滴、添加化学物质促进脂质代谢以及通过调控脂质代谢相关基因的表达降低脂质含量。作者简要阐述了过高的脂质含量引起卵母细胞和胚胎冷冻损伤的机制,总结了离心去脂法与化学去脂法的原理、应用效果以及局限性,并探讨了通过调控脂质代谢相关基因的表达从而去脂的可能性,以期为开发更稳定的卵母细胞和胚胎冷冻技术提供一定的参考。

Cryopreservation of oocytes and embryos can be combined with reproduction techniques such as superovulation and embryo transfer to break the limitations of physiology,region and time on the reproductive potential of female animals,which is of great significance for international circulation of germplasm,propagation of excellent domestic animals and conservation of germplasm of endangered animals.However,oocytes or embryos are prone to membrane damage,endoplasmic reticulum and mitochondrial damage and lipid peroxidation during cryopreserved process due to the abundant lipid content,which reduces their developmental ability after thawing and greatly limits the application of cryopreserved oocytes and embryos.Many researches have shown that reducing the lipid content of oocytes or embryos before cryopreservation is beneficial for improving the survival rate,blastocyst rate,and pregnancy rate of them after thawing.At present,there are three popular methods to reduce lipid content such as removing lipid droplets by micromanipulation after polarization by centrifugation,promoting lipid metabolism by adding chemicals,and regulating the expression of genes related to lipid metabolism.In this review,the mechanisms of damages caused by high lipid content in oocyte and embryo were briefly expounded,the principles,effects and limitations of methods that reduce the content of lipids by centrifugation or chemicals were summarized,and the possibility of lipid removal by regulating the expression of genes related to lipid metabolism was discussed.This review could provide some reference for the development of more stable cryopreservation technology of oocyte and embryo.