Abstract: Bovine frozen semen were thawed and capacitated in vitro by heparin and caffeine for 1h. The ultrastructrual changes of sperm after capacitation were observed under transmission electron microscope. The results were as follows (1) Both of the bovine sperm acrosome inner membrane and outer membrane were double layered; (2) There were various patterns of acrosome viscularization after sperm capacitation, such as fusion of plasma membrane and acrosome outer membrane, self fusion of the double layered acrosome outer membrane, invagination of acrosome outer membrane or extrudation and fusion of double layered acrosome inner membrane; furthermore several vesicularization patterns could be seen in the same sperm acrosome reaction; (3) After capacitation, the post part of the sperm head nucleous membrane without acrosome covered expanded and fused with expanded plasma membrane; (4) After capactiation, the tail membrane expanded, and the mainpiece of the plasma membrane was much more expanded than that of the midpiece part, which may be related with hyperactivation.

Key words: Bovine sperm, Capacitation, Ultrastructure

摘要： 用肝素 咖啡因作获能剂对牛冷冻 解冻精子进行体外获能处理 ,体外培养 1h ,在透射电镜下观察精子获能后的超微结构变化。结果表明 :(1)牛精子顶体内膜和外膜均为双层膜结构 ;(2 )精子获能后顶体囊泡化的形成有多种形式 :质膜与顶体外膜融合 ,双层顶体外膜自身融合 ,顶体外膜内陷或外突打褶 ,双层顶体内膜自身融合 ,顶体内膜外突打褶形成囊泡 ;而且在同一精子的顶体反应中可同时出现多种囊泡化形式 ;(3)精子获能后 ,头部无顶体覆盖的核后区核膜膨胀 ,并与膨胀的质膜融在一起 ;(4 )精子获能后 ,尾部质膜膨胀 ,且主段质膜比中段质膜膨胀明显 ,这可能与超激活运动有关。

关键词: 牛精子, 获能, 超微结构