Department of Physiological Chemistry, The Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, Maryland 21205, USA.
Dev Biol. 1981 Jun;84(2):397-406. doi: 10.1016/0012-1606(81)90408-5.
We have examined the relationship between sperm adhesion and fertilization in the cross species insemination of Arbacia punctulata eggs by Strongylocentrotus purpuratus sperm. As previously reported (Kinsey et al., 1980) the addition of S. purpuratus egg jelly results in induction of the acrosome reaction in sperm and significant numbers of S. purpuratus sperm adhere to A. punctulata eggs. However, in the absence of S. purpuratus egg jelly, S. purpuratus sperm fail to bind to A. punctulata eggs. Although at least 200 S. purpuratus sperm bind to an A. punctulata egg in the presence of S. purpuratus jelly, less than 8% of the eggs are fertilized. The adhesion of S. purpuratus sperm meets the same functional criteria as homologous A. punctulata sperm-egg adhesion. Electron microscopy shows that S. purpuratus sperm that have undergone the acrosome reaction adhere to A. punctulata eggs by their bindin-coated acrosomal process in a manner that is morphologically identical to that observed with homologous A. punctulata sperm. We have also compared the ability of S. purpuratus and A. punctulata sperm to fuse and fertilize with A. punctulata eggs after removal of the vitelline layer. Using high levels of sperm of either species, heterologous as well as homologous fertilization is readily detectable. Under these conditions, where stable binding is not demonstrable, there is no difference in the ability of S. purpuratus and A. punctulata sperm to fertilize A. punctulata eggs. These observations suggest that the failure of S. purpuratus sperm to fertilize A. punctulata eggs under normal conditions may be due to their inability to penetrate the vitelline layer so that they can fuse with the egg plasma membrane. In relation to the possible mechanism of vitelline layer penetration, we have also investigated the mode of action of chymostatin, an inhibitor of chymotrypsin that has been reported to inhibit fertilization of sea urchin eggs (Hoshi et al., 1979). Our findings suggest that the fertilization inhibitory activity of chymostatin is not related to its antichymotrypsin activity. Rather, it appears that this inhibition is due to the induction of an abnormal acrosome reaction in sperm that precludes formation of the acrosome process.
我们研究了在十字对虾受精的交叉种内受精中精子附着与受精之间的关系。正如先前报道的那样（Kinsey 等人，1980 年），添加海胆卵 jelly 会诱导精子顶体反应，并使大量海胆精子附着在海胆卵上。然而，在没有海胆卵 jelly 的情况下，海胆精子无法附着在海胆卵上。尽管在海胆 jelly 的存在下至少有 200 个海胆精子附着在一个海胆卵上，但不到 8%的卵被受精。海胆精子的附着符合同源海胆精子-卵附着的相同功能标准。电子显微镜显示，经历顶体反应的海胆精子通过其结合蛋白覆盖的顶体过程附着在海胆卵上，这种方式在形态上与同源海胆精子观察到的方式相同。我们还比较了海胆精子和海胆精子去除卵黄层后与海胆卵融合和受精的能力。使用两种物种的高浓度精子，无论是同种异体还是同源受精都很容易检测到。在这些条件下，稳定结合无法证明，海胆精子和海胆精子受精海胆卵的能力没有差异。这些观察结果表明，在正常情况下，海胆精子不能使海胆卵受精，可能是由于它们无法穿透卵黄层，从而无法与卵质膜融合。关于卵黄层穿透的可能机制，我们还研究了糜蛋白酶抑制剂 chymostatin 的作用模式，该抑制剂已被报道可抑制海胆卵受精（Hoshi 等人，1979 年）。我们的发现表明，chymostatin 的受精抑制活性与其抗糜蛋白酶活性无关。相反，似乎这种抑制是由于诱导精子发生异常的顶体反应，从而阻止顶体过程的形成。
