Woolley D M, Nickels S N
J Ultrastruct Res. 1985 Mar;90(3):221-34. doi: 10.1016/s0022-5320(85)80001-0.
Detailed reconstructions of the flagellar tip (end-piece) in rodent spermatozoa have shown patterns of displacement between the termination points of the axonemal doublets (judging the terminations by the loss of electron density from the A-tubule). The patterns are in good agreement with those derived from sliding microtubule theory. In the hamster at least, the axis of major displacement passes approximately through doublet 1 and between doublets 5 and 6, though there may be some skewness in the clockwise direction. Microtubules derived from the plane at right angles to this (the central pair and presumably one or both of doublets 3 and 8) continue beyond the rest to the extreme tip, where they appear to be linked together at the cell membrane. This arrangement suggests that the tapering form of the end-piece, and of flagellar terminal filaments and ciliary tips in general, may be an adaptation to contain the sliding microtubules and prevent them impinging on the membrane overlying the tip.
对啮齿动物精子鞭毛尖端（末端）的详细重建显示了轴丝双联体终止点之间的位移模式（通过A微管电子密度的丧失来判断终止点）。这些模式与从微管滑动理论推导出来的模式高度一致。至少在仓鼠中，主要位移轴大致穿过双联体1，并在双联体5和6之间，尽管可能存在顺时针方向的一些偏斜。与该平面成直角的微管（中央微管对以及可能是双联体3和8中的一个或两个）比其他微管延伸得更远，直至极端尖端，在那里它们似乎在细胞膜处连接在一起。这种排列表明，末端的逐渐变细形式，以及一般的鞭毛末端丝和纤毛尖端，可能是一种适应性结构，用于容纳滑动的微管，并防止它们撞击覆盖在尖端的膜。
