Macháty Z, Mayes M A, Prather R S
Department of Animal Sciences, University of Missouri-Columbia 65211, USA.
Biol Reprod. 1995 Apr;52(4):753-8. doi: 10.1095/biolreprod52.4.753.
A possible mechanism by which sperm activate oocytes may involve a G protein-mediated signal-transducing pathway. Artificial stimulation of G proteins leads to events very similar to those at fertilization in oocytes of several species. Here we report the effects of activation of a G protein with guanosine-5'-O-(3'-thiotriphosphate) (GTP-gamma-S), a hydrolysis-resistant analog of guanosine triphosphate (GTP), in porcine oocytes. Mature oocytes were injected with 1 mM GTP-gamma-S. In response to injection, oocytes underwent changes normally occurring at fertilization, i.e. cortical granule exocytosis, changes in the protein synthetic profile, pronuclear formation, and development to the blastocyst stage. Guanosine-5'-O-(2-thiodiphosphate) (GDP-beta-S; a metabolically stable analog of guanosine diphosphate [GDP] that inactivates the G protein) and the carrier medium (CM; medium in which the injected compounds were dissolved) were significantly less effective in oocyte activation. It is suggested that porcine oocytes contain the components of a G protein-mediated signaling pathway that might function in oocyte activation at fertilization.
精子激活卵母细胞的一种可能机制可能涉及G蛋白介导的信号转导途径。人工刺激G蛋白会导致与几种物种卵母细胞受精时非常相似的事件。在此，我们报道了用鸟苷-5'-O-(3'-硫代三磷酸)(GTP-γ-S，鸟苷三磷酸(GTP)的一种抗水解类似物)激活猪卵母细胞中G蛋白的效果。将1 mM GTP-γ-S注射到成熟卵母细胞中。作为对注射的反应，卵母细胞发生了受精时正常发生的变化，即皮质颗粒胞吐、蛋白质合成谱的变化、原核形成以及发育到囊胚阶段。鸟苷-5'-O-(2-硫代二磷酸)(GDP-β-S；一种使G蛋白失活的鸟苷二磷酸[GDP]的代谢稳定类似物)和载体介质(CM；溶解注射化合物的介质)在卵母细胞激活方面的效果明显较差。有人提出，猪卵母细胞含有G蛋白介导的信号通路的成分，这些成分可能在受精时卵母细胞激活中发挥作用。
