包囊游仆虫细胞的类中间纤维细胞骨架体系

应用生化分级抽提，并结合DGD包埋 去包埋透射电镜样品制备方法显示，包囊游仆虫营养细胞和休眠细胞中，均存在由直径10 nm左右的单根纤维及单根纤维聚集成的纤维束为结构单元形成的类中间纤维细胞骨架体系.其中，营养细胞的类中间纤维构成的细胞质三维网架，在细胞膜内缘以较密集的纤维网占有了整个表质层，在表质层内缘的细胞质深部纤维形成较松散的网络，网内常见附着有细胞器及一些电子密度颗粒；核纤层位于大核核膜内缘，纤维紧密聚集成网；核骨架纤维网分布比较致密，未见有电子密度颗粒附着.休眠细胞中含有与营养细胞相似的纤维网架结构，但位于细胞内不同层次的纤维网比营养细胞中的同种结构要致密得多，这可能与纤毛虫形成包囊时细胞大范围的收缩有关.并且值得注意的是，在休眠细胞包囊壁的内层壁中也观察到相似于中间纤维的纤维网络，其纤维网均匀和致密地分布在整个包囊壁层中.电泳图谱显示，纤毛虫形成包囊后，保留了营养细胞中的部分蛋白条带，失去了部分条带，新产生了一些特异的条带.结果表明，包囊游仆虫的类中间纤维 核骨架体系，是细胞在营养条件下和休眠状态下都稳定存在的结构，它可能起到比微管类骨架更重要的作用.并且休眠细胞中该体系产生的一些特异蛋白条带，可能是纤毛虫休眠生命活动中的重要蛋白.

Intermediate Filament Matrix System of Vegetative Cell and Resting Cyst of Euplotes encysticus

By the combination of serial selective extraction,with diethylene glycol distearate (DGD) embedment and embedment-free electron microscopy,as well as SDS-PAGE,the inter- mediate filament (IF) matrix system,which is composed of the filament about 10 nm in diameter and filament band,was observed in vegetative cells and resting cysts of Euplotes encysticus.In vegetative cells,a three dimensions scaffold formed by IF occupies the whole epiplasm with den- ser filament network beneath the pellicle.The filament of cytoplasm deeps beneath the epiplasm makes up of a looser network attached by organelle and some dense electronic granules.The LA was a laminar structure,which was composed of parallel filaments.The nuclear matrix filament network distributes more intensively and no dense electronic granules attached.The similar more compact network is also seen in the resting cyst,which may be caused by the widely contraction in the course of encystment in infusorians.Remarkably,the filament network is also observed in the inner-cyst-wall of resting cyst,and its filament network distributes equably and densely in the whole cyst wall.SDS-PAGE shows that only parts of the proteins have preserved when the cyst is formed,part lost,and some distinct proteins have produced.Conclusions:the intermedi- ate filament-lamina-nuclear matrix system is a stable structure in both vegetative and resting cyst,and it may play a more important role than the microtubule matrix.Besides the special cin- gulums in this system of cyst may be the important proteins needed in resting cyst.