摘要
采用细胞成份的选择性抽提方法,结合常规电镜和DGD(Diethylene Glycol Distearate)包埋一去包埋电镜技术制备典型涡鞭毛虫前环藻的细胞核骨架,结果表明其核内存在一个蛋白性质的纤维网状结构,并且通过核纤层与中等纤维发生联系形成一个贯穿核质的骨架体系。即使在未经任何抽提处理的情况下,前环藻细胞的染色体之间仍然存在骨架结构。根据典型涡鞭毛虫的特点及细胞核骨架的定义,可以肯定其中包含了核骨架部分,这一实验结果排除了核骨架是因抽提处理造成结构假象的可能性;另外,在制备核骨架时,于选择性抽提液CSK液中加入1％巯基乙醇抑制二硫键的形成,结果同样观察到核内有一个致密的纤维网络结构,并且与选择性抽提制备的核骨架相似,这也说明核骨架结构并不是由于蛋白质分子间二硫键的交联而造成的结构假象。以上结果都证明核骨架是一个真实存在的结构。
With DGD embedment sectioning and embedment-free technique, We found that nuclear matrix also could be demonstrated in the nucleus of typical dinoflagellate Amphidinium carterae after a series of selective extractions and DNase treatment. The morphology of the nuclear matrix is similar to that of higher eukaryotic cells, and consisting a non-chromatin filamentous network and granular structures. However, it is noteworthy that, with DGD technique, even in the cells fixed directly without any prior extractions and treatments, a similar dense network of filaments could also be demonstrated in the nucleoplasma. It has long been known that, in typical dineflagellate nucleus, almost all of the DNA concentrate in the permanently condensed chromosomes. Therefore, at least most of the filaments are not chromatin fibrils, but nuclear matrix filaments. Besides, when the formation of sulfide links among protein molecules was protected by adding 1 % mercaptoethol into the extraction buffer, the nuclear matrix also could be demonstrated. This fact rules out the possiblity that the nuclear matrix is an artifact produced by the formation of difulfide links among protein molecules. These facts above imply that the nuclear matrix in typical dineflagellate is a real physiological nuclear structure, rather than artifact produced during extractions and treatments.
基金
国家自然科学基金
关键词
典型涡鞭毛虫
前环藻
细胞核骨架
Typical dinoflagellate, Amphidinium carterae, Nuclear matrix, Selective extraction, DGD embedment sectioning and embedment-free technique
