Longo F J, Georgiou C, Cook S
Department of Anatomy, University of Iowa, Iowa City 52242.
Gamete Res. 1989 Aug;23(4):429-40. doi: 10.1002/mrd.1120230408.
Observations, employing freeze fracture replication and electron microscopic immunochemistry, have been carried out to determine structural correlations of the plasma membrane domain occupied by a 210 kDa protein involved in the acrosomal reaction of sea urchin sperm and recognized by the monoclonal antibody, J10/14 (Trimmer et al.: Cell 40:697-703, 1985; Proceedings of the National Academy of Sciences of the United States of America 83: 9055-9059, 1986). Immunogold-J10/14 staining of acrosome-intact sperm was intense along the flagellum and a narrow collar just posterior to the sperm apex that surrounded the acrosomal complex (acrosomal vesicle and subjacent anterior nuclear fossa containing g-actin). Counts of gold particles revealed a density (average number of particles/micron2 of surface area) eightfold greater along the plasma membrane associated with the acrosomal complex than membrane delimiting the remainder of the sperm head. The collar of J10/14 staining was isomorphic with a dense aggregation of intramembranous particles in the P-face of the plasma membrane and a thin cytoplasmic region that surrounded the acrosomal complex. In acrosome-reacted sperm, intense J10/14 staining was distributed along the flagellum and sperm head; prominent anterior staining was not apparent in all specimens. The density of gold particles associated with plasma membrane delimiting components of the former acrosomal complex, nucleus and mitochondrion, as well as the total average number of particles along the entire sperm surface, were increased in sperm acrosome-reacted with A-23187. Concomitant with this change in staining was the disappearance/reduction of the collars of intramembranous particles and cytoplasm. These observations indicate that plasma membrane components (210 kDa protein and intramembranous particles) and the collar of cytoplasm which are associated with the acrosomal complex are functionally, as well as structurally related. Analyses of particle density distributions along acrosome- and non-acrosome-reacted sperm suggest that the different staining patterns observed may be brought about by the recognition of cryptic sites at the time of the acrosomal reaction.
运用冷冻断裂复型和电子显微镜免疫化学技术进行了观察，以确定海胆精子顶体反应中涉及的一种210 kDa蛋白质所占据的质膜区域的结构相关性，该蛋白质可被单克隆抗体J10/14识别（特里默等人：《细胞》40:697 - 703，1985；《美国国家科学院院刊》83: 9055 - 9059，1986）。完整顶体精子的免疫金 - J10/14染色在鞭毛以及精子顶端后方围绕顶体复合体（顶体小泡和含有γ - 肌动蛋白的相邻前核窝）的一个狭窄环带上很强。金颗粒计数显示，与顶体复合体相关的质膜上的密度（每平方微米表面积的平均颗粒数）比界定精子头部其余部分的膜上密度大八倍。J10/14染色的环带与质膜P面的膜内颗粒密集聚集以及围绕顶体复合体的薄细胞质区域同构。在顶体反应后的精子中，强烈的J10/14染色分布在鞭毛和精子头部；并非所有标本都有明显的前部染色。与先前顶体复合体、细胞核和线粒体的界定成分的质膜相关的金颗粒密度，以及整个精子表面的颗粒总平均数，在与A - 23187发生顶体反应的精子中增加。伴随着这种染色变化的是膜内颗粒和细胞质环带的消失/减少。这些观察结果表明，与顶体复合体相关的质膜成分（210 kDa蛋白质和膜内颗粒）以及细胞质环带在功能和结构上都是相关的。对顶体反应和未反应精子的颗粒密度分布分析表明，观察到的不同染色模式可能是由顶体反应时隐蔽位点的识别引起的。
