Courtot A M, Feinberg J M, Schoevaert D A, Rainteau D P, Weinman S J
Laboratoire de Biologie de la Reproduction et du Développement, CHU Bicétre, Kremlin-Bicêtre, France.
Mol Reprod Dev. 1994 Jun;38(2):170-7. doi: 10.1002/mrd.1080380208.
In the present study, immunogold labeling of ultrathin sections of human sperm, before and after incorporation into hamster oocyte, was used to obtain insight into the ultrastructural localization and possible function of calmodulin during fertilization. In heads of ejaculated, capacitated, and acrosome-reacted fixed human sperm, calmodulin was mainly found in two compartments, the subacrosomal layer and the postacrosome. After sperm-egg fusion, the subacrosomal calmodulin was unaltered and surrounded by the fertilization cone in which actin was abundant. There was no co-localization of calmodulin and actin. In contrast, postacrosomal calmodulin disappeared as soon as the sperm head was incorporated into egg cytoplasm. These unique localizations and redistributions are in agreement with the concept of a calmodulin targeting from acrosome toward postacrosome through the subacrosomal layer during spermatogenesis (Weinman et al., 1986b: J Histochem Cytochem 34:118). Moreover, they strongly suggest a role for calmodulin both in sperm-egg fusion and in the initial pulse of Ca2+ occurring during fertilization.
在本研究中，通过对人精子超薄切片进行免疫金标记（在精子与仓鼠卵母细胞融合前后），来深入了解受精过程中钙调蛋白的超微结构定位及其可能的功能。在射出的、获能的以及顶体反应后的固定人精子头部，钙调蛋白主要存在于两个区域，即顶体下区域和顶体后区域。精卵融合后，顶体下的钙调蛋白未发生变化，并被富含肌动蛋白的受精锥所包围。钙调蛋白与肌动蛋白没有共定位。相反，一旦精子头部进入卵细胞质，顶体后的钙调蛋白就会消失。这些独特的定位和重新分布与精子发生过程中钙调蛋白从顶体通过顶体下区域向顶体后区域靶向定位的概念相符（Weinman等人，1986b：《组织化学与细胞化学杂志》34：118）。此外，它们强烈提示钙调蛋白在精卵融合以及受精过程中发生的初始钙离子脉冲中均发挥作用。
