Ji W, Bavister B D
Kunming Institute of Zoology, the Chinese Academy of Sciences, China.
Theriogenology. 2000 Oct 1;54(6):827-34. doi: 10.1016/S0093-691X(00)00394-0.
The zona pellucida (ZP) enclosing the mammalian ovum is important for its protection and for initial stages of fertilization, but the role of the ZP during embryo development is less clear. This study was designed to investigate if the hamster ZP is needed for embryo development from 1-cell to blastocyst in vitro, and to compare methods for removing the ZP. A total of 395 hamster pronucleate ova were collected 10 h post activation from superovulated, mated female hamsters. The ZP was removed from some ova using either 0.05% pronase, 0.05% trypsin or acid Tyrode's solution. To prevent ZP-free ova from sticking together, they were cultured singly in 30-50 microL drops of HECM-6 culture medium together with ZP-intact ova as controls. There was no significant difference among treatment groups in embryo development to blastocyst: 36/87 (42%) in the ZP intact group; 35/75 (47%) in the pronase-treated ZP-free group; 37/74 (50%) in the trypsin-treated ZP-free group; and 37/71 (52%) in the acid-treated ZP-free group. These results indicate that 1) the ZP is unnecessary for hamster embryo development in vitro from the pronucleate ovum stage to blastocyst; 2) none of the three ZP-removal methods was detrimental to embryo development; 3) embryos do not need to be cultured in groups during in vitro development from 1-cell to blastocyst.
包裹哺乳动物卵子的透明带（ZP）对卵子的保护及受精初始阶段很重要，但透明带在胚胎发育过程中的作用尚不清楚。本研究旨在调查体外培养仓鼠胚胎从单细胞期发育至囊胚期是否需要透明带，并比较去除透明带的方法。从超排、交配后的雌性仓鼠体内收集激活10小时后的395枚原核卵子。使用0.05%的链霉蛋白酶、0.05%的胰蛋白酶或酸性台氏液从部分卵子上去除透明带。为防止无透明带卵子黏附在一起，将它们与完整透明带卵子作为对照，单独培养于30 - 50微升的HECM - 6培养基液滴中。各处理组胚胎发育至囊胚的情况无显著差异：完整透明带组为36/87（42%）；链霉蛋白酶处理的无透明带组为35/75（47%）；胰蛋白酶处理的无透明带组为37/74（50%）；酸性处理的无透明带组为37/71（52%）。这些结果表明：1）体外培养仓鼠胚胎从原核卵子阶段发育至囊胚期不需要透明带；2）三种去除透明带的方法均对胚胎发育无害；3）胚胎从单细胞期发育至囊胚期的体外培养过程中无需分组培养。
