Laboratori de Parasitologia, Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII, sn, 08028, Barcelona, Spain.
Parasitol Res. 2011 May;108(5):1283-93. doi: 10.1007/s00436-010-2178-2. Epub 2010 Dec 3.
We present the first ultrastructural description of spermiogenesis and of the spermatozoon of Rubenstrema exasperatum (Omphalometridae), an intestinal parasite of Sorex araneus (Soricidae). Spermiogenesis begins with the formation of the differentiation zone delimited at the base by the ring of the arched membranes and bordered by cortical microtubules. This area contains two centrioles associated with striated rootlets and with an intercentriolar body. It also contains the nucleus and numerous mitochondria. The intercentriolar body is made up of seven electron-dense layers. The two centrioles give rise to two free flagella that grow orthogonally to the median cytoplasmic process. Additionally, flagellar rotation is followed by the proximodistal fusion of the flagella with the median cytoplasmic process, while the nucleus and mitochondria migrate along the spermatid. The constriction of the ring of arched membranes gives rise to the young spermatozoon. The mature spermatozoon of R. exasperatum shows several ultrastructural characters found in digenean spermatozoa such as two axonemes, mitochondrion, two bundles of parallel cortical microtubules, nucleus, and granules of glycogen. External ornamentation of the plasma membrane and spinelike bodies are also present in the spermatozoon of this species. In the present study, we produced additional spermatological data concerning a previously unexplored family, and we also compare our data to the existent ultrastructural descriptions within the Digenea in order to assess the use of several characters proposed as phylogenetic tools.
我们首次描述了 Rubenstrema exasperatum（Omphalometridae）的精子发生和精子超微结构，这是一种 Sorex araneus（Soricidae）肠道寄生虫。精子发生始于分化区的形成，分化区由拱形膜的环限定在底部，由皮质微管包围。该区域包含两个与纹状根相连的中心粒，以及一个中心粒间体。它还包含核和许多线粒体。中心粒间体由七个电子致密层组成。两个中心粒产生两个自由鞭毛，它们与中央细胞质过程正交生长。此外，鞭毛旋转后，鞭毛与中央细胞质过程近端-远端融合，而核和线粒体沿着精细胞迁移。拱形膜环的收缩产生了年轻的精子。R. exasperatum 的成熟精子表现出几种在复殖类精子中发现的超微结构特征，例如两个轴丝、线粒体、两个平行皮质微管束、核和糖原颗粒。该物种的精子还存在质膜的外部装饰和类似刺的体。在本研究中，我们提供了关于一个以前未被探索的科的额外的精子学数据，并且我们还将我们的数据与现存的复殖类的超微结构描述进行了比较，以评估几个被提议作为系统发育工具的特征的使用。
