日本沼虾精子的形态和超微结构研究

THE MORPHOLOGY AND ULTRASTRUCTURE OF THE SPERM OF THE FRESHWATER SHRIMP MACROBRACHIUM NIPPONENSE

应用电子显微镜技术结合细胞化学方法对日本沼虾精子进行了形态和超微结构研究。结果显示，日本沼虾精子形似外翻的伞状。无鞭毛、不运动的精子主要由前端棘突、中间帽状体和后主体部组成。精子的核属非浓缩型，内布许多絮状物质，外无核膜包被，呈Feulgen阳性反应，位于后主体部内；中间帽状体的细胞质内含有一对中心粒和15-20根放射状排列的纤丝，纤丝在帽状体凸面中央汇聚并延伸成精子的棘突。棘突和放射状纤丝皆具间隔约35nm的环纹以及与之相垂直的、直径约4－7nm的丝状体。精子无明显的顶体区域。

The morphology and ultrastructure of the sperm of the freshwater shrimp,Macrobrachium nipponense, were studied with electron microscopy and cytochemical cytochemical methods.The results show that the nonflagellated, nonmotile sperm resembles everted umbrella and is composed of spike-anterior in position, cap -shaped part at the middle and main-body part at the rear which contains a nucleus.The nucleus is decondensed and contains many flocculent materials.The nucleus is not delimited by a nuclear membrane and shows feulgen positive.The cytoplasm of the cap-shaped part contains a pair of centrioles which is composed of nine doublet tubules and 15-20 radial fibrils which anastomose to form the spike.Both the spike and the radial fibrils are cross-striated with a periodicity of 35 nm. These structures contain 4-7 nm filaments running perpendicularly to the cross striation. No clearly definable acrosomal region is identifiable morphologically.