Zribi Soumaya, Quilichini Yann, Tekaya Saïda, Marchand Bernard
Université de Tunis El-Manar, Faculté des Sciences de Tunis, UR11ES12 Biologie de la reproduction et du développement animal, 2092 El Manar, Tunis, Tunisia.
UMR SPE 6134, CNRS - Université de Corse, Service d'Etude et de Recherche en Microscopie Electronique, 20250 Corte, France.
Micron. 2014 Nov;66:80-6. doi: 10.1016/j.micron.2014.06.002. Epub 2014 Jun 12.
The mature spermatozoa of Perinereis macropus were investigated by transmission electron microscopy. The spermatozoon is composed with a large anterior part (head), a short middle piece and a long flagellum. The head contains a large acrosomal complex with a convex acrosomal vesicle, a subacrosomal space, a fibrillar crown and an acrosomal rod which penetrates into the nucleus invagination. The later is U shaped (in longitudinal section). The short middle piece contains about nine to eleven mitochondria and a centriole associated with the flagellum. This centriole, slightly eccentric to the sperm axis, anchors to the plasma membrane by nine satellite rays of the pericentriolar complex. The axoneme has a "9+2″ arrangement of microtubules. In cross section, the flagellar membrane extends in two lateral protuberances, aligned with the axis formed by the two central microtubules of the axoneme. The spermatozoon of P. macropus conforms to the primitive type with an acrosomal extension. Nevertheless, the acrosome complex ultrastructure shows noticeable modifications from the basic form. This finding agrees with the previously observed reproductive pattern (broadcast spawning - free-swimming larvae), and may be helpful to classify the sperm type of P. macropus.
利用透射电子显微镜对大围沙蚕成熟精子进行了研究。精子由一个大的前部（头部）、一个短的中段和一条长鞭毛组成。头部包含一个大型顶体复合体，其具有一个凸起的顶体泡、一个顶体下腔、一个纤维冠和一根穿透核内陷的顶体杆。核内陷呈U形（纵切面）。短的中段包含约九到十一个线粒体和一个与鞭毛相关的中心粒。这个中心粒相对于精子轴稍有偏心，通过中心粒周围复合体的九条卫星射线锚定在质膜上。轴丝具有“9+2”微管排列。在横切面上，鞭毛膜向两个侧向突起延伸，与由轴丝的两个中央微管形成的轴对齐。大围沙蚕的精子符合具有顶体延伸的原始类型。然而，顶体复合体的超微结构显示出与基本形式明显的差异。这一发现与先前观察到的繁殖模式（散播产卵 - 自由游动幼虫）一致，可能有助于对大围沙蚕的精子类型进行分类。
