Chaly N, Setterfield G, Kaplan J G, Brown D L
Biol Cell. 1983;49(1):35-43. doi: 10.1111/j.1768-322x.1984.tb00220.x.
Nuclear bodies (NB) are poorly understood nucleoplasmic structures frequently observed in many animal cell types. Murine lymphocytes mitogenically stimulated with concanavalin A contain 5 types of NB. In order to examine the origin and function of the NB we have carried out cell fractionation and have performed cytochemistry, immunocytochemistry and autoradiography at the electron microscope level. Regressive staining for RNP showed that simple NB (types I and II) and the shells of complex NB (types III, IVa and V) consist of a non-chromatinic fibrillar material which is most likely proteinaceous. Projections of this material from the NB surface appear to link the NB to nucleoplasmic fibrogranular elements. The fibrillar, filamentous and granular components of the cores of complex NB were largely RNP and in some instances closely resembled fibrogranular areas in the nucleoplasm. Chromatin masses were seen occasionally in the cores. All NB types remained unstained after nucleolus-specific silver nitrate staining, and were also not stained by a centromere-specific antibody. Autoradiography was performed along long-term labelling with 3H-uridine, 3H-thymidine or 3H-leucine. The NB were not labelled by any of the precursors, indicating that macromolecular synthesis does not play a major role in NB evolution in these cells. By fractionation, we showed that NB co-isolated with the nuclear matrix, and were linked to the fibrogranular nuclear matrix component by projections from the surface of the NB. A possible role of NB in RNA processing is discussed.
核体（NB）是在许多动物细胞类型中经常观察到但却知之甚少的核质结构。用伴刀豆球蛋白A进行有丝分裂刺激的小鼠淋巴细胞含有5种类型的核体。为了研究核体的起源和功能，我们进行了细胞分级分离，并在电子显微镜水平上进行了细胞化学、免疫细胞化学和放射自显影。对核糖核蛋白（RNP）的退行性染色显示，简单核体（I型和II型）以及复杂核体（III型、IVa型和V型）的外壳由一种非染色质的纤维状物质组成，这种物质很可能是蛋白质性的。这种物质从核体表面伸出的部分似乎将核体与核质纤维颗粒成分连接起来。复杂核体核心的纤维状、丝状和颗粒状成分主要是RNP，在某些情况下与核质中的纤维颗粒区域非常相似。偶尔在核心中可见染色质团块。所有类型的核体在核仁特异性硝酸银染色后均未染色，也未被着丝粒特异性抗体染色。用3H-尿苷、3H-胸腺嘧啶核苷或3H-亮氨酸进行长期标记后进行放射自显影。核体未被任何一种前体标记，这表明大分子合成在这些细胞的核体演化中不起主要作用。通过分级分离，我们发现核体与核基质共分离，并通过核体表面的突起与纤维颗粒状核基质成分相连。文中讨论了核体在RNA加工中的可能作用。
