ULTRASTRUCTURAL STUDIES ON BIGELOWIELLA NATANS, GEN. ET SP. NOV., A CHLORARACHNIOPHYTE FLAGELLATE
ULTRASTRUCTURAL STUDIES ON BIGELOWIELLA NATANS, GEN. ET SP. NOV., A CHLORARACHNIOPHYTE FLAGELLATE
复制标题
BIGELOWIELLA NATANS 将军的超微结构研究
DOI：
10.1046/j.1529-8817.2001.037004624.x
复制
发表时间：
2001
影响因子：
2.9
通讯作者：
M. Sengco
中科院分区：
文献类型：
--
作者：
Ø. Moestrup;M. Sengco
来自毕格罗实验室的普罗瓦索利 - 吉拉德国家海洋浮游植物培养中心的三个分离株，先前被标记为来自绿藻纲柄球藻目的柄球藻属（Pedinomonas sp.）和微小柄球藻（Pedinomonas minutissima），已经通过光学显微镜和透射电子显微镜进行了检查，结果显示它们属于绿蜘藻纲（Chlorarachniophyceae），这是一类含有核形的变形虫。这三个分离株是首次被发现的绿蜘藻纲的鞭毛虫。细胞的超微结构已经被详细检查，特别强调了鞭毛器，这是之前在绿蜘藻中没有被详细检查过的一个特征。细胞基本上是双鞭毛的，但第二条鞭毛仅由一个非常短的基体代表。鞭毛复制表明这条鞭毛是成熟阶段，即1号鞭毛，而伸出的长鞭毛是2号鞭毛，在细胞分裂期间它会缩短成一个短基体。有丝分裂是开放式的，在每一极都有一对中心粒。在有丝分裂期间没有伸出的鞭毛。细胞可能会形成包囊，并且鞭毛基体和部分鞭毛根在包囊中得以保留。四条微管根从基体发出，其中一条的路径非常不寻常，与任何其他已知的鞭毛虫都很不一样。没有观察到有条纹的根。细胞的其他精细结构特征包括一种非常不寻常的蛋白核类型和一种特殊类型的挤出体。细胞是混合营养型的。这三个分离株非常相似，被描述为新属新种的纳氏毕格罗藻（Bigelowiella natans, gen. et sp. nov.）。在超微结构上，绿蜘藻与任何已知的藻类或其他原生生物类群都没有密切的关系。
Three isolates from the Provasoli‐Guillard National Center for Culture of Marine Phytoplankton at Bigelow Laboratory, previously labeled Pedinomonas sp. and Pedinomonas minutissima from the green algal class Pedinophyceae, have been examined by light microscopy and TEM and shown to belong to the Chlorarachniophyceae, a class of nucleomorph‐containing amebae. The three isolates represent the first chlorarachniophycean flagellates to be discovered. The ultrastructure of the cells has been examined in detail, with particular emphasis on the flagellar apparatus, a feature not examined in detail in chlorarachniophytes before. Cells are basically biflagellate, but the second flagellum is represented by a very short basal body only. Flagellar replication has shown this flagellum to be the mature stage, that is, the no. 1 flagellum, whereas the long emergent flagellum is the no. 2 flagellum that shortens into a short basal body during cell division. Mitosis is open with a pair of centrioles at each pole. Emergent flagella are absent during mitosis. Cells may form cysts, and the flagellar basal bodies and part of the flagellar roots are maintained in the cysts. Four microtubular roots emanate from the basal bodies, and the path of one of them is very unusual and very unlike any other known flagellate. No striated roots were observed. Other fine‐structural features of the cell include a very unusual type of pyrenoid and a special type of extrusome. Cells are mixotrophic. The three isolates are very similar and are described as Bigelowiella natans, gen. et sp. nov. Ultrastructurally, chlorarachniophytes do not show close relationship to any known group of algae or other protists.