Fouquet J P, Fraile B, Kann M L
Laboratoire d'Histologie, UFR Biomédicale, Paris, France.
Anat Rec. 1991 Nov;231(3):316-23. doi: 10.1002/ar.1092310304.
The distribution of actin and CaM in hamster spermatozoa was examined during the early events of fertilization using postembedding immunogold procedures. Actin was immunolocalized with a polyclonal antibody and two monoclonal antibodies. CaM was immunodetected with a polyclonal antibody. In epididymal sperm, actin labeling was found solely in the principal piece of the flagellum. CaM labeling was observed in the postacrosomal lamina, subacrosomal ring, and tip of the perforatorium. These distributions were not modified after capacitation and acrosome reaction. During the successive steps of sperm-egg fusion actin remained undetected in the sperm head whereas its location did not change in the flagellum. CaM distribution remained unmodified until the sperm head begins to decondense. At later stages of sperm head decondensation the postacrosomal lamina and its CaM labeling disappeared, whereas gold particles were still detected in the subacrosomal layer. The predominant location of actin into the egg cortex, particularly the microvillus-free area was confirmed. Except for the CaM labeling of the meiotic spindle, no special CaM location could be found throughout the egg. Thus, in hamster, a role for sperm actin in sperm-egg fusion appears unlikely. In contrast the CaM present in the Ca(2+)-rich postacrosomal lamina could be involved in the regulation of egg activation.
利用包埋后免疫金标技术，在受精早期事件中检测了肌动蛋白和钙调蛋白在仓鼠精子中的分布。用一种多克隆抗体和两种单克隆抗体对肌动蛋白进行免疫定位。用一种多克隆抗体免疫检测钙调蛋白。在附睾精子中，肌动蛋白标记仅见于鞭毛的主段。在顶体后层、顶体下层环和穿孔器尖端观察到钙调蛋白标记。获能和顶体反应后，这些分布没有改变。在精卵融合的连续步骤中，精子头部未检测到肌动蛋白，而其在鞭毛中的位置没有变化。钙调蛋白分布在精子头部开始解聚之前保持不变。在精子头部解聚的后期，顶体后层及其钙调蛋白标记消失，而在顶体下层仍能检测到金颗粒。证实了肌动蛋白在卵皮质中的主要位置，特别是无微绒毛区域。除了减数分裂纺锤体的钙调蛋白标记外，在整个卵子中未发现特殊的钙调蛋白定位。因此，在仓鼠中，精子肌动蛋白在精卵融合中似乎不太可能起作用。相反，富含钙离子的顶体后层中的钙调蛋白可能参与卵子激活的调节。
