Rieder C L
J Cell Biol. 1979 Jan;80(1):1-9. doi: 10.1083/jcb.80.1.1.
The distribution of ribonucleoprotein (RNP) within the mitotic spindle of newt lung epithelial cells was studied with the high voltage electron microscope (HVEM) using Bernhard's uranyl-EDTA-lead staining of thick sections in conjunction with the ribonuclease digestion of fixed cells. The results indicate that aside from ribosomes, the major RNP-containing components of the spindle are the kinetochores and centrioles, both of which stain electron-opaque after EDTA treatment. In both cases, the electron-opaque material associated with these microtubule organizing centers (MTOC's) can be removed by RNAse digestion and cold perchloric acid (PCA) extraction under conditions which leave the spindle microtubules (Mts) centrioles, and kinetochores intact. The staining reaction is not abolished by cold PCA extraction alone or by substituting other positively charged proteins (i.e., cytochrome c or lysozyme) for RNAse. The RNP component of the kinetochore is closely associated with the bases of the kinetochore microtubules. The RNP component of the centriole can be seen to surround the microtubules of the triplet blades. No evidence was found to indicate the presence of RNP in the pericentriolar material. The possible function of both kinetochore and centriolar RNP is discussed.
利用高压电子显微镜（HVEM），结合对固定细胞进行核糖核酸酶消化，采用伯恩哈德氏铀酰 - 乙二胺四乙酸 - 铅对厚切片染色的方法，研究了蝾螈肺上皮细胞有丝分裂纺锤体中核糖核蛋白（RNP）的分布。结果表明，除核糖体外，纺锤体中含主要RNP的成分是动粒和中心粒，经乙二胺四乙酸处理后二者均呈现电子不透明。在这两种情况下，与这些微管组织中心（MTOC）相关的电子不透明物质可通过核糖核酸酶消化以及在使纺锤体微管（Mts）、中心粒和动粒保持完整的条件下用冷高氯酸（PCA）提取来去除。单独的冷PCA提取或用其他带正电荷的蛋白质（即细胞色素c或溶菌酶）替代核糖核酸酶并不会消除染色反应。动粒的RNP成分与动粒微管的基部紧密相关。可看到中心粒的RNP成分围绕着三联体叶片的微管。未发现有证据表明在中心粒周围物质中存在RNP。本文讨论了动粒和中心粒RNP的可能功能。
