Quilichini Yann, Foata Joséphine, Orsini Antoine, Marchand Bernard
Laboratory Parasites & Mediterranean Ecosystems, Faculty of Sciences and Technics, University of Corsica, F-20250 Corte, Corse, France.
J Parasitol. 2007 Jun;93(3):469-78. doi: 10.1645/GE-1085R.1.
Spermiogenesis and ultrastructure of spermatozoon of Nicolla wisniewskii (Digenea, Opecoelidae), an intestinal parasite of Salmo trutta, were studied by electron microscopy. Spermiogenesis follows the general pattern found in the Digenea. It begins with the formation of a differentiation zone, including striated rootlets associated with 2 centrioles and an intercentriolar body. The flagella undergo a rotation of greater than 90 degrees. Then, their fusion with the median cytoplasmic process is proximodistal and asynchronous. A peculiarity was observed before the fusion of flagella, i.e., the attachment zones joined as 2 pairs by an electron-dense bridge. The mature spermatozoon is characterized by 2 axonemes, cortical microtubules, a nucleus, 2 mitochondria, external ornamentation, and spinelike bodies. At the posterior end of flagella, the spermatozoon is also characterized by the presence of a central element of the axoneme and without the 9 microtubule doublets. These results were compared with those of the other digeneans and, in particular, with other species of Opecoelidae. It appears that the number of cortical microtubules and their localization in the spermatozoon may be an interesting feature of their phylogeny.
利用电子显微镜研究了鲑鱼肠道寄生虫维斯涅夫斯基尼科吸虫（复殖目，孔肠科）精子的发生过程和精子超微结构。精子发生遵循复殖目动物的一般模式。它始于分化区的形成，包括与两个中心粒和一个中心粒间体相关的横纹小根。鞭毛发生大于90度的旋转。然后，它们与中间细胞质突起的融合是从近端到远端且不同步的。在鞭毛融合之前观察到一个特殊现象，即附着区通过一个电子致密桥以两对的形式相连。成熟精子的特征是有两个轴丝、皮质微管、一个细胞核、两个线粒体、外部纹饰和刺状体。在鞭毛的后端，精子的特征还在于轴丝中央元件的存在且没有9个微管二联体。将这些结果与其他复殖目动物的结果进行了比较，特别是与孔肠科的其他物种进行了比较。看来皮质微管的数量及其在精子中的定位可能是它们系统发育的一个有趣特征。
