二硫苏糖醇对刺参卵母细胞体外成熟的影响

用海星鞘神经提取液和二硫苏糖醇对刺参卵母细胞进行了体外人工促熟研究。结果显示,二硫苏糖醇对刺参卵母细胞具有明显的促熟作用。刺参卵母细胞包被在滤泡中发育,卵母细胞通过动物极的卵突起连接到单层细胞构成滤泡膜上,充分发育的卵母细胞处于生发泡期,染色质凝集在核仁周围,处于生发泡期的卵母细胞在海水中不会自发成熟。用二硫苏糖醇处理充分发育的卵母细胞20min,卵母细胞的生发泡开始移动,并锚定在卵母细胞的动物极,继而出现生发泡破裂。此后,减数分裂重新启动,第一、二极体分别排出。但海星鞘神经提取液对刺参卵母细胞没有促熟作用。实验表明,二硫苏糖醇浓度在10-5～10-1mol/L范围内,均可促使刺参卵母细胞发生生发泡破裂,10-2mol/L时诱导卵母细胞成熟率可达90%以上。

DTT induction of oocyte maturation in the sea cucumber Apostichopus japonicus (slenka)

Water-extracts of radial nerves from the starfish and dithiothreitol (DTT) were used to induce the oocyte maturation of the sea cucumber Apostichopus japonicus (slenka). Although radial nerve extracts failed to induce oocyte maturation in the sea cucumber, breakdown of germinal vesicles and subsequent meiotic behavior of chromosomes were induced by the treatment with DTT. Oocytes of the sea cucumber A. japonicus are arrested at the germinal vesicle (GV) stage and do not start maturation spontaneously, after being treated with DTT for 20 min, the GV begins to migrate to the animal pole of the oocyte, then the GV breaks down, that is called germinal vesicle breakdown (GVBD). Meiosis of the oocyte reinitiated and two polar bodies protrude out successively. DTT with the condensation of 10-1 mol/L to 10-5 mol/L can successfully induce GVBD. Maturation ratio can reach to 90% when the condensation of the DTT solution is 10-2 mol/L, oocytes induced to maturation can be fertilized, while they can not develop normally.