Miller M G, Mulholland D J, Vogl A W
Department of Environmental Toxicology, University of California, Davis, California 95616, USA.
Biol Reprod. 1999 Apr;60(4):1047-56. doi: 10.1095/biolreprod60.4.1047.
In this study, we report sites in the seminiferous epithelium of the rat testis that are immunoreactive with antibodies to the intermediate chain of cytoplasmic dynein and kinesin II. The study was done to determine whether or not microtubule-dependent motor proteins are present in Sertoli cell regions involved with spermatid translocation. Sections and epithelial fragments of perfusion-fixed rat testis were probed with an antibody (clone 74.1) to the intermediate chain of cytoplasmic dynein (IC74) and to kinesin-II. Labeling with the antibody to cytoplasmic dynein was dramatically evident in Sertoli cell regions surrounding apical crypts containing attached spermatids and known to contain unique intercellular attachment plaques. The antibody to kinesin II reacted only with spermatid tails. The levels of cytoplasmic dynein visible on immunoblots of supernatants collected from spermatid/junction complexes treated with an actin-severing enzyme (gelsolin) were greater than those of controls, indicating that at least some of the dynein may have been associated with Sertoli cell junction plaques attached to spermatids. Results are consistent with the conclusion that an isoform of cytoplasmic dynein may be responsible for the apical translocation of elongate spermatids that occurs before sperm release. Also, this is the first report of kinesin-II in mammalian spermatid tails.
在本研究中，我们报告了大鼠睾丸生精上皮中与胞质动力蛋白中间链和驱动蛋白II抗体发生免疫反应的位点。进行这项研究是为了确定参与精子细胞易位的支持细胞区域是否存在微管依赖性运动蛋白。用针对胞质动力蛋白中间链（IC74）和驱动蛋白II的抗体（克隆74.1）探测灌注固定的大鼠睾丸切片和上皮片段。用针对胞质动力蛋白的抗体标记在含有附着精子细胞且已知含有独特细胞间附着斑的顶端隐窝周围的支持细胞区域中显著可见。驱动蛋白II抗体仅与精子细胞尾部发生反应。用肌动蛋白切割酶（凝溶胶蛋白）处理精子细胞/连接复合体后收集的上清液免疫印迹中可见的胞质动力蛋白水平高于对照组，表明至少部分动力蛋白可能与附着在精子细胞上的支持细胞连接斑相关。结果与胞质动力蛋白的一种同工型可能负责精子释放前伸长精子细胞的顶端易位这一结论一致。此外，这是关于驱动蛋白II在哺乳动物精子细胞尾部的首次报道。
