Mugnier Sylvie, Dell'Aquila Maria Elena, Pelaez Jesus, Douet Cécile, Ambruosi Barbara, De Santis Teresa, Lacalandra Giovanni Michele, Lebos Claude, Sizaret Pierre-Yves, Delaleu Bernadette, Monget Philippe, Mermillod Pascal, Magistrini Michèle, Meyers Stuart A, Goudet Ghylène
Institut National de la Recherche Agronomique, UMR85, Physiologie de la Reproduction et des Comportements, Nouzilly, France.
Biol Reprod. 2009 Nov;81(5):856-70. doi: 10.1095/biolreprod.109.077651. Epub 2009 Jul 8.
The mechanism of fertilization remains largely enigmatic in mammals. Most studies exploring the molecular mechanism underlying fertilization have been restricted to a single species, generally the mouse, without a comparative approach. However, the identification of divergences between species could allow us to highlight key components in the mechanism of fertilization. In the pig, in vitro fertilization (IVF) and polyspermy rates are high, and spermatozoa penetrate easily through the zona pellucida (ZP). In contrast, IVF rates are low in the horse, and polyspermy is scarce. Our objective was to develop a comparative strategy between these two divergent models. First, we compared the role of equine and porcine gametes in the following five functions using intraspecific and interspecific IVF: ZP binding, acrosome reaction, penetration through the ZP, gamete fusion, and pronucleus formation. Under in vitro conditions, we showed that the ZP is a determining element in sperm-ZP attachment and penetration, whereas the capacity of the spermatozoa is of less importance. In contrast, the capacity of the spermatozoa is a key component of the acrosome reaction step. Second, we compared the composition and structure of the equine and porcine ZP. We observed differences in the number and localization of the ZP glycoproteins and in the mesh-like structure of the ZP between equine and porcine species. These differences might correlate with the differences in spermatozoal attachment and penetration rates. In conclusion, our comparative approach allows us to identify determining elements in the mechanism of fertilization.
在哺乳动物中，受精机制在很大程度上仍然是个谜。大多数探索受精背后分子机制的研究都局限于单一物种，通常是小鼠，缺乏比较研究方法。然而，识别物种间的差异可以使我们突出受精机制中的关键成分。在猪中，体外受精（IVF）和多精入卵率很高，精子很容易穿透透明带（ZP）。相比之下，马的体外受精率很低，多精入卵的情况也很少见。我们的目标是在这两种不同的模型之间开发一种比较策略。首先，我们使用种内和种间体外受精比较了马和猪配子在以下五种功能中的作用：ZP结合、顶体反应、穿透ZP、配子融合和原核形成。在体外条件下，我们发现ZP是精子-ZP附着和穿透的决定性因素，而精子的能力则不那么重要。相比之下，精子的能力是顶体反应步骤的关键组成部分。其次，我们比较了马和猪ZP的组成和结构。我们观察到马和猪物种之间ZP糖蛋白的数量和定位以及ZP的网状结构存在差异。这些差异可能与精子附着和穿透率的差异相关。总之，我们的比较方法使我们能够识别受精机制中的决定性因素。
