González-García J M, Benavente R, Rufas J S
Departamento de Biología, Universidad Autónoma de Madrid, Spain.
Eur J Cell Biol. 1996 Aug;70(4):352-60.
In the present paper we have analyzed the trilaminar kinetochores present in the mitotic holocentric chromosomes of the heteropteran Graphosoma italicum by means of different cytochemical and immunocytochemical techniques at the ultrastructural level. The results obtained after EDTA and osmium tetroxide/p-phenylenediamine, both cytochemical methods for preferential detection of ribonucleoproteins, show that the inner and outer kinetochore layers are selectively contrasted. These results agree with those previously reported for the kinetochores of monocentric chromosomes. Additionally, using cytochemical techniques such as ethanolic phosphotungstic acid staining and silver impregnation, which recognize proteins, we report a different response of the inner kinetochore layer compared with those obtained in the middle and outer layers. Finally, our immunoelectron microscopic results employing monoclonal antibodies against DNA indicate the absence of this component from the kinetochore plates in holocentric chromosomes. Although the trilaminar appearance of kinetochores in holocentric chromosomes is very similar to that of the localized kinetochores in mammals, our observations imply the existence of significant differences on the macromolecular organization of both types of kinetochores.
在本论文中，我们借助不同的细胞化学和免疫细胞化学技术，在超微结构水平上分析了异翅目昆虫意大利扁喙叶蝉有丝分裂全着丝粒染色体中存在的三层动粒。采用乙二胺四乙酸（EDTA）和四氧化锇/对苯二胺这两种优先检测核糖核蛋白的细胞化学方法所获得的结果表明，动粒的内层和外层被选择性地染色。这些结果与先前关于单着丝粒染色体动粒的报道一致。此外，使用诸如乙醇磷钨酸染色和银浸染等能识别蛋白质的细胞化学技术，我们发现动粒内层与中层和外层呈现出不同的反应。最后，我们运用抗DNA单克隆抗体的免疫电子显微镜结果表明，全着丝粒染色体的动粒板中不存在该成分。尽管全着丝粒染色体中动粒的三层结构外观与哺乳动物局部动粒的外观非常相似，但我们的观察结果表明这两种类型的动粒在大分子组织上存在显著差异。
