Macháty Z, Funahashi H, Mayes M A, Day B N, Prather R S
Department of Animal Sciences, University of Missouri-Columbia 65211, USA.
Biol Reprod. 1996 Feb;54(2):316-22. doi: 10.1095/biolreprod54.2.316.
In vitro-matured porcine oocytes were given injections of 0.1 M CaCl2 and after 6 h evaluated for signs of early and late activation events. CaCl2 injection caused cortical granule exocytosis in 75% (3 of 4) of the oocytes tested. It also induced cell cycle resumption as monitored by the histone H1 kinase assay: the phosphorylation rate of histone H1 decreased to 36.7% of the original value. Treated oocytes completed meiosis, extruded the second polar body, and progressed to first interphase: 79.4% of them formed one or more pronuclei. The elevated intracellular Ca2+ level resulted in activation-related changes in the protein synthetic profile in 90% (9 of 10) of the oocytes. Furthermore, 14.7% (9 of 61) of the treated oocytes developed to the compact morula/early blastocyst stage after a 7-day culture in ligated porcine oviduct, and one blastocyst hatched from the zona pellucida. Control oocytes given injections of 0.1 M MgCl2 or carrier medium (10 mM Hepes) did not show the changes mentioned. The results strengthen the idea that Ca2+ is a cell messenger that plays a central part in oocyte activation; it is concluded that elevated intracellular Ca2+ level caused by a single injection of CaCl2 leads to both early and late events of porcine oocyte activation.
对体外成熟的猪卵母细胞注射0.1M氯化钙，6小时后评估早期和晚期激活事件的迹象。氯化钙注射导致75%（4个中的3个）受试卵母细胞发生皮质颗粒胞吐作用。通过组蛋白H1激酶测定监测，它还诱导了细胞周期恢复：组蛋白H1的磷酸化率降至原始值的36.7%。处理后的卵母细胞完成减数分裂，排出第二极体，并进入第一次间期：其中79.4%形成了一个或多个原核。细胞内钙离子水平升高导致90%（10个中的9个）卵母细胞的蛋白质合成谱发生激活相关变化。此外，在结扎的猪输卵管中培养7天后，14.7%（61个中的9个）处理后的卵母细胞发育到致密桑葚胚/早期囊胚阶段，一个囊胚从透明带孵化出来。注射0.1M氯化镁或载体培养基（10mM Hepes）的对照卵母细胞未显示上述变化。这些结果强化了钙离子是在卵母细胞激活中起核心作用的细胞信使这一观点；得出的结论是，单次注射氯化钙导致的细胞内钙离子水平升高会引发猪卵母细胞激活的早期和晚期事件。
