Evaluation of oocytes activation by oocyte-ativating factors derived from sperm extract.

在哺乳动物卵母细胞中，受精相关的钙离子[Ca~(2+)]i振荡负责激活发育。有人提出，精子可能与卵母细胞质膜上的受体相互作用，参与细胞内导致钙释放的信号通路。另一种研究表明，在精子-卵母细胞融合时，精子胞质因子被释放到卵母细胞中，与未知的胞浆目标相互作用，并产生[Ca+]i振荡。在这项研究中，我们证明了将异种精子粗提物(SF)注射到其他哺乳动物卵母细胞中可以激活和体外孤雌发育。我们在受精时的信号转导机制中支持的一个假说认为，精子中的一个因子(SF)被释放到卵子中，并通过与未知的胞浆靶点相互作用，产生卵母细胞的激活。将各种精子注射到仓鼠、小鼠、兔子、猪和牛的卵母细胞(This Me…在我们的研究中，有更多的配子膜融合被绕过)激活的卵母细胞与受精过程中观察到的相似。为了进一步检验SF的生理学相关性，将猪精子注射到金黄地鼠卵母细胞中，获得SF。它是引起原核形成的，但与正常的仓鼠受精相比，形成是延迟的。这可能是由于受精后的仓鼠卵母细胞振荡频率高于猪卵母细胞所致。因此，如果SF含有[Ca~(2+)]i振荡的生理启动子，则将一种SF注射到不同物种的卵母细胞中应该能够在这些卵母细胞中诱导钙反应，并且应该尊重每个物种的模式特征。长时间的振荡是哺乳动物受精的特征，也是激活胚胎发育的关键。它可能是由精子胞质因子触发的。例如，这一途径的刺激可用于胚胎克隆中的孤雌生殖激活，其抑制可能为避孕提供见解。较少

In mammalian oocytes, fertilization-associated calcium [Ca2+]i oscillations are responsible for the activation of development. It has been proposed that the sperm may interact with receptors in the oocyte's plasma membrane and engage intracellular signaling pathways that result in Ca2+ release. A different line of investigation suggests that upon sperm-oocyte fusion, a sperm cytosolic factor is released into the oocyte which interacts with unknown cytosolic targets, and generates [Ca2+]i oscillations. In this study, we demonstrated that injections of xeno-sperm crude extracts (SF) into other mammalian oocytes couses activation and in vitro parthenogenetic development. A hypothesis we supported in the mechanism of signal transduction at fertilization proposes that a factor from the sperm (SF) is released into the egg and, by interacting with unknown cytosolic targets, generates activation of oocytes. Injection of various sperm into hamster, mouse, rabbit, pig and bovine oocytes (this me … More ans that gametes' membrane fusion was by-passed) activated oocytes similar to those observed during fertilization, in our study. To further test the physiological relevance of SF,SF is obtained from porcine sperm were injected into hamster oocytes. It was caused pronuclear formation but formation is delayd compared to that of normal hamster fertilization. Probably it was due to fertilized hamster oocytes oscillate with higher frequency than porcine oocytes. Thus, if SF contains a physiological initiator of [Ca2+]i oscillations, injection of SF from one species into oocytes of a different species should be able to induce Ca2+ responses in these oocytes and it should respect the pattern characteristic of each species. Long lasting oscillations are characteristic of mammalian fertilization and they are critical for the activation of embryonic development. It may triggered by sperm cytosolic factors. For example, stimulation of this pathway may be used for parthenogenetic activation in embryo cloning and its inhibition may offer insights in contraception. Less