Brunanská M, Nebesárová J, Scholz T, Fagerholm H P
Parasitological Institute, Slovak Academy of Sciences, Kosice, Slovak Republic.
Parasitol Res. 2002 Apr;88(4):285-91. doi: 10.1007/s00436-001-0532-0.
The fine structure of the mature spermatozoon of the pseudophyllidean tapeworm Eubothrium crassum, a parasite of salmonid fishes, has been studied by transmission electron microscopy for the first time. The mature spermatozoon of E. crassum is filiform and tapered at both extremities. It contains two axonemes of unequal length showing the 9 + "1" pattern of Trepaxonemata. The anterior extremity exhibits a crested body 50-100 nm thick. It spirals around the outside of the anterior region of the spermatozoon. The nucleus is electron-dense, exhibiting a fibrous appearance in its middle (the broadest) region. The cortical microtubules are of two types and are situated parallel to the spermatozoon axis. The cytoplasm is slightly electron-dense and contains numerous electron-dense granules in region II of the spermatozoon. A ring of electron-dense, centred microtubules surrounds the axoneme, together with the underlying ring of moderately electron-dense, subjacent submicrotubular material in region V. The anterior and posterior extremities of the spermatozoon lack cortical microtubules and contain a single axoneme. Our results reveal several peculiarities, in which the spermatozoon of E. crassum differs from those of other pseudophyllidean cestodes.
首次通过透射电子显微镜对鲑科鱼类寄生虫——粗茎真叶绦虫成熟精子的精细结构进行了研究。粗茎真叶绦虫的成熟精子呈丝状，两端逐渐变细。它含有两条长度不等的轴丝，呈现出Trepaxonemata的9 + “1”模式。前端有一个厚50 - 100纳米的嵴状体。它围绕着精子前端区域的外部螺旋缠绕。细胞核电子密度高，在其中间（最宽）区域呈现出纤维状外观。皮质微管有两种类型，与精子轴平行排列。细胞质电子密度略高，在精子的区域II中含有许多电子致密颗粒。在区域V中，一圈电子致密的中心微管围绕着轴丝，连同其下方一层中等电子密度的亚微管物质的环。精子的前端和后端没有皮质微管，只含有一条轴丝。我们的结果揭示了粗茎真叶绦虫精子与其他假叶目绦虫精子不同的几个特点。
