日本血吸虫精子的超微结构

ULTRASTRUCTURE OF SCHISTOSOMAJAPONICUM SPERM

目的：了解日本血吸虫正常精子的超微结构。方法：半超薄切片定位雄虫睾丸和含有成熟精子的雌虫输卵管，常规透射电镜制样并观察。结果：日本血吸虫精子由头、尾两部分组成，头部呈长卵圆形，平均长６．２μｍ，宽１．４μｍ，无顶体构造，前端钝圆，后端尖细，质膜下有１圈纵行的微管，核１个，前端有少量线粒体，尾部鞭毛１根，在中、后段主体部分鞭毛轴丝外周为９组二联管，中央为一团弥散的电子致密物质，呈９×２＋《１》型；但在过渡区鞭毛轴丝中央无电子致密物质，呈９×２＋０型。结论：日本血吸虫精子超微结构与其他血吸虫相似，具有同源性，但明显区别于复殖目大多数吸虫的构造。

AIM: To understand the ultrastructure of Schistosoma japonicum sperm. METHODS: Testis and oviduct were cut from male and female of S.japonicum respectively, location was assured by observing with microscope. Specimens preparation for transmission electron microscope were made by traditional way. RESULTS: The sperm of S.japonicum includes two parts: a head and a single tail. The elongated ovoid head measures by 6 2×1 4 μm, lacking an acrosome, rounding anteriorly and tapering posteriorly. A prominent anterior mass of mitochondria lies beneath the plasma membrane. A layer of microtubes under the plasma membrane are parallel with long axis of the head. A coil of longitudinal microtubes were present beneath the plasma membrane. The nucleus is largely electron opaque with some electron lucent patches or less electron dense material. The tail is a single flagellum with a unique axoneme, which originated from a centriole. The axoneme in main part of the flagellum (including middle and posterior parts of the tail) consists of nine doublets and a single diffuse central structure, forming 9×2+《1》 type. But the axoneme in the transition area (anterior part of the tail) lacks central material, forming 9×2+0 type. CONCLUSION: The sperm ultrastructure in the schistosomes is homogeneous, but differs distinctly from those trematodes of other Digenea.