条斑星鲽精子超微结构研究

Study on spermatozoon ultrastructure of barfin flounder Verasper moseri

中文关键词: 条斑星鲽  精子  超微结构  核前凹陷

英文关键词: Verasper moseri  Ultrastructure  Spermatozoon  Anterior pit of the nucleus

中文摘要:

      分别以扫描电镜和透射电镜方法研究了条斑星鲽精子的超微结构。条斑星鲽精子全长45.57±3.23μm，主要包括三部分：头部、中段和鞭毛。头部呈圆形，主要结构为近圆形的细胞核；中段不发达，主要包括线粒体和中心粒复合体两部分，具有多个未分化的圆形小线粒体；鞭毛细长，结构为典型的“9+2”型双联微管结构，无侧鳍。这些特征表明，条斑星鲽的精子属于简单的原始类型。条斑星鲽精子不具顶体，但具有开口于核前端稍偏处呈不规则状的核前部凹陷及核内核泡结构，核前凹陷与染色质区无界膜分隔，部分精子在凹陷前端存在由核膜构成的凸起。凹陷区的前部及其开口处常有多个小的具单层界膜的囊泡，这些结构可能是顶体的遗迹，但也不排除其是向外释放核内物质的一种途径的可能性。

英文摘要:

      The ultrastructure of barfin flounder Verasper moseri spermatozoon was studied with scanning microscopy and trans mission electron microscopy. Total length of the sperm is 45.57±3.23μm (n=11), and the sperm includes three parts: head, mid piece and flagellum. The spherical head mainly consists of the nearly circular cell nucleus. The mid piece is composed of mitochondria and center grain complex, with some round undifferentiated small mitochondria. The typical ‘9+2’ pattern of the flagellum has quite simple structure, which means that the spermatozoon of barfin flounder can be classified as a primitive type, which is found in most of the advanced fish taxa. But the anterior vesicles and pit of the nucleus of this spermatozoon have seldom reported from other species. There is no acrosome in the sperm. At anterolateral to the nucleus, there is a chromatin free, electron lucent area, which was named the anterior pit of the nucleus. Within and in front of the pit, an irregular shaped structure and some different sized vesicles that are encapsulated in a layer of membrane were found. With regard to acrosome and acrosome vestige present in some other euteleosts, we presume that the vesicles may represent acrosome vestiges though they may also function to release nuclear material, while the irregular shaped structure in front of the nucleus may be caused by improper sample preparation