特殊涡鞭毛虫——尖尾藻的核骨架

THE NUCLEOSKELETON OF SPECIAL DINOFLAGELLATE, Oxyrrhis marina

采用分级抽提,DGD包埋-去包埋剂电镜技术在特殊涡鞭毛虫——尖尾藻的细胞核内显示出了一个纤维网络结构。此网络结构不溶于CSK液和可抽去微管与微丝的溶液,不被DNase所酶解和热三氯醋酸所抽提,因而是一个非DNA性质的纤维蛋白网络结构。它的一系列形态结构特征——整个呈网络形态,纤维的粗细为2.8—24nm,与细胞质内的中间纤维有广泛的连接,含有少量对维持其结构完整性所必需的RNA成分等,都十分相似于典型真核细胞的核骨架结构,但所显示的核纤层为一层不均匀、不连续的结构,这有别于典型真核细胞的核纤层。 本工作首次证实了特殊涡鞭毛虫——尖尾藻已进化产生了核骨架结构,且与典型真核细胞的核骨架在形态结构上已很接近。

A network was shown in the nucleus of special dinoflagellate, Oxyrrhis marina, by serial selective extrations, diethylene glycol distearate (DGD) embedment sectioning and embedment-free electron microscopy. This reticular structure could resist against the extractions of CSK buffer and the buffer which always removes microtubules and microfilaments from the cells. It could also resist against the digestion of DNase and the treatment of hot trichloroacctic acid (5%, 90-91℃, 15min). Therefore, it must be a non-DNA fibrous protein structure. Its reticular form, the thickness of the filaments (2.8-24 nm), connection with intermediate filaments in cytoplasm and the containing of a small amount of RNA which is necessary in keeping its spatial organization etc, are very similar to those of the nucleoskeleton of typical cukaryotes. However, the lamina of Oxyrrhis marina is not a well-distributed layer as the lamina in typical eukaryotic cells, but a discontinuous imcomplete layer. The nucleoskeleton was first demonstrated in the nucleus of a special dinoflagellate, Oxyrrhis rnarina.