小眼虫的核骨架研究

小眼虫细胞经轻度超声处理、选择性抽提后，利用DGD包埋－－去包埋剂电镜技术及Western blot分析技术对其核骨架、核纤层进行了研究。结果显示：细胞核内存在一个不被DNase所降解和热三氯醋酸所去除的纤维蛋白性网架结构；核的周围有一层明显的核纤层结构；Western blot分析表明其核纤层有两种阳性蛋白成分，一为相当于高等真核细胞核纤层蛋白lamin B的强阳性成分，另一为相当于lamin A的弱阳性成分，但无相当于lamin C的成分。本文认为小眼虫这种低等的单细胞真核生物已具有了核骨架、核纤层结构，其核纤层的蛋白组成应该代表了核纤层进化历程中早期的一个阶段。

NUCLEAR MATRIX AND NUCLEAR LAMINA OF EUGLENA GRACILIS

Lightly sonicated E. gracilis cells were extracted sequentially, and then their nuclear matrix and nuclear lamina were investigated by DGD embedment-free electron microscopy and Western blot analysis. The results showed that in the nucleus there were a fibrous network and a layer of lamina beneath the nuclear membrane, both of which could not be removed by DNase and hot trichloroacetic acid. Western blot analysis(with polyclonal antiserum against three lamins of rat liver) showed that its nuclear lamina possessed a major and a minor positive polypeptides, which were similar to mammalian lamin B and lamin A respectively. It was suggested that the lower unicellular eukaryote E. gracilis already had nuclear matrix and nuclear lamina, its lamina polypeptide(lamin) should reflect a historical stage of nuclear lamina evolution.