奶牛精子尾部颈段的超微结构

奶牛精子尾部颈段的中央结构是连接片(connecting piece).连接片具横纹,由踝状突(capitulum)和9条节柱(segmented columns)构成。踝状突位于核后端的植入窝中。踝状突的腹面与节柱相连。有3条节柱在近踝状突腹面处聚集成为一条较大的节柱,与踝状突前端的腹面相连。另有2条节柱也在近踝状突腹面聚集成为另一条较大的节柱,与踝状突后端的腹面相连。其余4条节柱与踝状突两侧的腹面相连。9条节柱的末端分别与9条外周致密纤维(outer dense fibers)相连。近端中心粒位于踝状突之中,远端中心粒分裂成为9条柱状结构。每条柱状结构分别依附于每一条节柱与外周致密纤维连接处的内侧。在远端中心粒的中央有轴丝的两条中央微管和两条内棒(internal robs)。在连接片的外侧方还有线粒体。线粒体不形成线粒体鞘。

The Ultrastructure of the Neck Region of Bovine Sperm Tail

The central structure of the neck region of bovine sperm tail is connecting piece. The connecting piece is Cross-striated. It consists of capitulum and nine segmented columns. The capitulum is inside the implantation fossa. The segmented columns are connected with the ventral side of the capitulum. Three segmented columns coalesce into a major column, which merges with the ventral side of the anterior end of the capitulum. Two columns also coalesce into another major column, which merges with the ventral side of the posterior end of the capitulum. Four segmented columns merge with the capitulum sideways. Nine segmented columns overlap the tapering anterior ends of nine outer dense fibers. The proximal centri01e is inside the capitulum. The distal centriole divides into nine columns, each of which adheres to the inner side of every segmented column. At the center of the distal centriole there is central fiber of axoneme and two internal robs. Outside the connecting piece there are some mitochondria, which do not form mitochondrial sheath.