Sato S, Willson C, Dickinson H G
Department of Biology, Faculty of Science, Ehime University, Japan.
Biol Cell. 1988;64(3):321-9. doi: 10.1016/0248-4900(88)90006-8.
Cytohistochemical staining and RNase-gold labelling have been applied to root-tip meristematic cells of Vicia faba to study the origin and biological significance of 2 types of inclusions: one seen in the nucleoplasm and the other in the cytoplasm of early telophase cells. They have been termed "dense bodies" and "cytoplasmic nucleolus-like bodies" (NLB), respectively. Both types of inclusions respond positively to silver staining and ribonucleoprotein (RNP) staining in a similar fashion to nucleolus. Interestingly, the dense bodies label heavily with the RNase-gold complex, as does the nucleolus, while the cytoplasmic NLB have no affinity with the label. In most cases, the dense bodies label more heavily than the nucleolus. Light microscope surveys reveal that the dense bodies sometimes appear to be released from the surface of the nucleolus. On the other hand, prenucleolar material showing the same silver staining and RNP preferential staining characteristics as the dense bodies begin to accumulate on the surface of chromosomes in mid-anaphase. This material does not label with RNase-gold. These data are discussed in terms of the hypothesis that the dense bodies are derived from the nucleolus by direct budding or fragmentation, and the cytoplasmic NLB are composed of prenucleolar material that failed to attach to chromosomes.
细胞组织化学染色和核糖核酸酶-金标记已应用于蚕豆根尖分生组织细胞，以研究两种内含物的起源和生物学意义：一种见于核质中，另一种见于末期早期细胞的细胞质中。它们分别被称为“致密体”和“细胞质核仁样体”（NLB）。这两种内含物对银染色和核糖核蛋白（RNP）染色的反应均呈阳性，方式与核仁相似。有趣的是，致密体与核仁一样，被核糖核酸酶-金复合物大量标记，而细胞质NLB与该标记无亲和力。在大多数情况下，致密体的标记比核仁更重。光学显微镜观察显示，致密体有时似乎是从核仁表面释放出来的。另一方面，在后期中期，显示出与致密体相同的银染色和RNP优先染色特征的核仁前体物质开始在染色体表面积累。这种物质不能被核糖核酸酶-金标记。根据致密体是通过直接出芽或断裂从核仁衍生而来，以及细胞质NLB由未能附着于染色体的核仁前体物质组成这一假说，对这些数据进行了讨论。
