有轮瑞利绦虫(圆叶目:戴维科)精子的超微结构

【目的】构建有轮瑞利绦虫Raillietina cesticllus精子的超微结构示意图。【方法】利用透射电镜技术,对寄生于鸡消化道的有轮瑞利绦虫的精子形态和结构特征进行观察。【结果】有轮瑞利绦虫的精子呈丝状,两端渐尖,具有冠状体,无线粒体,具有"9+1"类型的轴丝。精子从头至尾可划分为5区:I区,头部,具冠状体;II区,皮层微管明显,围轴鞘和蛋白质样横隔壁出现;III区,大量电子致密颗粒出现;IV区,细胞核出现;V区,尾部,轴丝游离。有轮瑞利绦虫和棘槽瑞利绦虫R.echinobothrida的精子具有1个冠状体,其他6种已报道的戴维科绦虫的精子均有2个冠状体;而有轮瑞利绦虫和棘槽瑞利绦虫精子冠状体的旋转角度不同,分别是40°~55°和35°。【结论】精子头部冠状体的数目和旋转角度可以将有轮瑞利绦虫和其他7种戴维科绦虫区分开来。

Ultrastructure of spermatozoon of Raillietina cesticllus (Cyclophylidea: Davaineidae)

[Objective] To illustrate the ultrastructure of the spermatozoon of Raillietina cesticllus.[Method]Transmission electron microscope was used to observe the morphorlogy and structure of the spermatozoon of R.cesticllus parasitized in chicken intestine.[Result]The spermatozoon of R.cesticllus is filiform, tapers at both ends, has crested-like body and lacks the mitochondria.It has axonemes with the "9+1" pattern.Based on longitudinal sections of R.cesticllus spermatozoon, five regions could be distinguished.RegionⅠcorresponds to the anterior extremity of the spermatozoon, having a crested-like body.RegionⅡ is characterized by the presence of cortical microtubules, a periaxonemal sheath and intracytoplasmic walls.Region Ⅲ has plenty of electro-dense granules.Region Ⅳ is characterized by the presence of the nucleus.RegionⅤcorresponds to the posterior end of the spermatozoon, having free flagellums.The spermatozoons of R.cesticllus and R.echinobothrida each has one crested-like body, while the spermatozoons of all other six reported davaineid cestode each has two crested-like bodies.The rotation angle of the crested-like body of R.cesticllus is 40°to 55°, other than 35° for R.echinobothrida.[Concluison]The number and rotation angle of the crested-like body of the spermatozoon head can descriminate R.cesticllus from other seven reported Davaineidae cestode.