玻璃化冷冻对哺乳动物卵母细胞Ca2+的影响机制

卵母细胞冷冻保存是胚胎生物技术(如体外受精、胞浆内单精子注射、体细胞克隆)的重要组成部分,对优良种畜和濒危动物种质资源保存,加速家畜品种改良进程都具有重要意义。与常规冷冻法相比,玻璃化冷冻具有操作简单、降温速率快、耗时短、冷冻效率高等优点,被越来越广泛地应用于家畜卵母细胞的冷冻保存。然而,与新鲜卵母细胞相比,玻璃化冷冻卵母细胞的受精率及发育能力仍不理想,这严重影响了玻璃化冷冻卵母细胞的应用潜力。玻璃化冷冻会引起卵母细胞Ca²⁺浓度升高及钙振荡模式异常,导致其透明带硬化、受精信号紊乱等问题。综合前人研究进展,作者分析了玻璃化冷冻对胞内Ca²⁺浓度、钙振荡模式的影响和作用机制,并指出胞外Ca²⁺内流和胞内钙库Ca²⁺释放是导致冷冻卵母细胞胞内Ca²⁺浓度升高的主要原因,1,4,5-三磷酸肌醇(IP3)Ⅰ型受体分布异常和线粒体损伤可能是导致冷冻卵母细胞钙振荡模式异常的重要原因,以期为正向调控冷冻卵母细胞Ca²⁺浓度及钙振荡模式提供技术参考,从而进一步提高玻璃化冷冻卵母细胞的受精和后续的发育能力。

The Influencing Mechanism of Vitrification on the Intracellular Calcium of Mammalian Oocytes

Oocyte cryopreservation is an important part of embryo biotechnologies (e.g.in vitro fertilization,intracytoplasmic sperm injection and somatic cell nuclear transfer),and is of a great significance in conserving the germplasm resources of excellent and endangered animals,accelerating the process of livestock breed improvement.Compared with the conventional freezing method,vitrification has many advantages,such as fast cooling rate and high efficiency,and is widely used in oocyte cryopreservation.However,fertilization and developmental competence of vitrified oocytes are still not ideal,which seriously affects the application of vitrified oocytes.Vitrification leads to increased calcium ion (Ca²⁺) concentration and abnormal Ca²⁺ oscillation pattern in oocytes,which hardens their zona pellucida and disorders their fertilization signal.By integrating previous findings,present paperanalyzed the influence and mechanism of vitrification on intracellular Ca²⁺ concentration and Ca²⁺ oscillation pattern,and proposed that extracellular Ca²⁺ influx and intracellular Ca²⁺ release induced by vitrification led to Ca²⁺ increasing in vitrified oocytes,and inositol 1,4,5-triphosphate (IP3) Ⅰ receptor maldistribution and mitochondrial damage led to abnormal Ca²⁺ oscillation pattern in vitrified oocytes.Above information may provide technical reference for researchers to regulate Ca²⁺ concentration and Ca²⁺ oscillation pattern positively in vitrified oocyte,and further improve their fertilization and subsequent developmental competence.