有关研究证实,游仆类的银线系在超微结构水平上对应了由微管束构成的网络骨架结构,关于其在纤毛虫细胞分裂过程中的发生模式鲜有报道。本工作应用银浸染色法和扫描电镜术,以扇形游仆虫(Euplotes vannus)、镰游仆虫(Euplotes harpa)和包囊游仆虫(Euplotes encysticus)为代表,研究了游仆类纤毛虫3种类型皮层银线系的形态发生过程。研究表明,游仆虫3种类型银线系的形态发生过程呈现基本相同的模式:该3种纤毛虫新银线网在棘毛原基基体周围发生,据此推测口围带小膜、棘毛基体复合单元和背触毛基体单元不仅对相应纤毛器结构行使微管组织中心作用,也可能对相应皮层区银线网的发生具有定位和组织中心的作用;围绕在基体左侧的银线网先于右侧开始发育,据此推测银线系的分化可能也具有方向性;腹面银线系发生中离新结构发生区近的老结构先瓦解,由此使新结构不断延伸发展,据此推测老银线网对新结构的形成可能起到诱导及定向作用;背面银线系发生中在每一背触毛列的中部范围相邻2列新背触毛间的老银线网消失,背触毛左、右两侧的新银线网会合形成新银线网,并且前仔虫前半部分和后仔虫后半部分的老银线网保留下来共同组成新细胞的背面银线网,由此表明,其老银线网参与了新结构的组成并对新结构的形成具有物质贡献。
The silver-line system of Euplotes corresponds to the cytoskeleton network,which is composed of microtubules at the ultrastructure level,and its morphogenesis pattern during cell division is rarely reported.Based on the application of silver nitrate impregnation and scanning electron microscopy,and using E.vannus,E.harpaand E.encysticus as the representatives,the morphogenesis of three types of cortical silver-line systems in genus Euplotes was examined in this study.The result showed that the morphogenesis of three types of cortical silver-line systems in the genus Euplotes shared the following features:the ventral silver-line system occurred around the new membranelles and the fragmented frontoventral-transverse anlagen;and the dorsal silver-line system occurred around the basal bodies of the dorsal bristle primordia.Thus,it was speculated that the composite element of basal bodies was not only microtubule organizing center,but also the center of the silver-line system.The new meshwork on the left of the basal bodies developed ahead of the meshwork on the right,thus,it was speculated that the silver-line system oriented similarly with ciliary organelles during their morphogenesis.In addition,the old meshwork near new silver-line first disintegrated,which led to the new silver-line system to develop constantly.It was assumed that the old silver-line system played a role of induction and orientation in the formation of new structure.The old silver-line system locating in the first half of the proter and in the latter part of the opisthe was reserved to form the dorsal silver-line system in new cells.It was supposed that the old silver-line system participated in the formation of new structure and also had a material contribution to it.