【摘要】 绵羊精子尾部颈段主要由关节头、节柱、近端中心粒、内棒、远端中心粒、轴丝的中央微管、外周致密纤维、线粒体等组成，外包有质膜。经分析发现，绵羊精子尾部颈段结构不稳固，其中，关节头与细胞核连接处，关节头与节柱连接处和节柱与外周致密纤维吻合处较易发生断裂更多还原

【Abstract】 Under the transsion electron microscope,ultrastructure of neck region of ram sperm tail was observed by ultramicrotoming technique. It mainly consists of capitulum, proximal centriole, internal robs, central pair of the axoneme, distal centriole, segmented columns, mitochondrion and outer dense fibers. Outside of the sperm is membrane. According to analysis. the weak links were as fellows:the connecting pieces between capitulu and nucleus,transition between capitulum and segmented dense columns,and tally between segmented columns and outer fibers. They were easily broken and formed the sperm without tail or head.更多还原