家兔胚胎细胞核移植影响因素的研究

STUDIES ON THE AFFECTING FACTORS OF NUCLEAR TRANSPLANTATION IN RABBIT EMBRYOS

母兔超数排卵后分别收集卵母细胞及交配后的１６－细胞胚，通过显微操作及电融合方法将１６－细胞胚的细胞核移入去核的成熟卵母细胞中，经培养使其发育。实验结果表明：１．注卵裂球胚的电融合率随温度的降低而降低，当温度由２２℃降至１２℃时，融合率由７０．８％降到３４．７％；２．一次电刺激后未发生融合的注卵裂球胚胎再次电刺激时，其融合率显著降低，由５１．３％降至１０．５％；３．不同次实验中，当融合率高时，该次实验移核胚的发育率也高；４．电刺激可以诱发兔卵子的皮质反应；５．１６－细胞胚卵裂球与去核卵母细胞融合后，其细胞核发生膨胀，形状不规则；６．随移核胚的发育，线粒体由嵴较少的圆球形变为嵴丰富的长棒状；７．移核胚发育到囊胚期时，内细胞团细胞以桥粒相连，滋养层细胞以紧密连接相连。

Superovulation in the female rabbit was conducted to obtain MII oocytes and 16-cell embryos.Nuclei from 16-cell embryos were transplanted into the enueleated oocytes by micromanipulation and electrofusion,and the nuclear transplant(NT)embryos were cultured in the oviducts of the intermediate recipient does.The results were as follows. (1)The fusion rate of oocyte-blastomere pairs was significiently lower at 12℃ than that of at 22℃ .(2)The fusion rate of the oocyte blastomere pairs which were not fused for the first time decreased remarkably when they were pulsed for the second time.(3)The developmental rate of the NT embryos was significiently higher when the fusion rates were high (>60%)than that when the rates were low (<60 %) . (4)Electric stimulation induced the repture of cortical granules in the rabbit oocyte.(5)Swelling and blebbing of donor nuclei occurred in the NT embryos.(6)The ultrastructure of the NT embryos was similar to that of the normal ones.