Eshel D, Gibbons I R
Pacific Biomedical Research Center, University of Hawaii, Honolulu 96813.
Cell Motil Cytoskeleton. 1989;14(3):416-23. doi: 10.1002/cm.970140311.
The movement parameters of a sea urchin sperm flagellum can be manipulated mechanically by applying various modes of periodic vibrations to the sperm head held by suction in the tip of a micropipette. The beat frequency of the flagellum readily synchronizes with the frequency of the externally imposed lateral vibration, and the plane of flagellar bending waves adapts itself to the plane of the pipette vibration (Gibbons et al., J. Cell Biol. 101:270a, 1985; Nature 325: 351-352, 1987). In this study, we observed the particular effects of external asymmetric forces on flagellar beating parameters by vibrating the micropipette holding the sperm head in a transverse sawtooth-like motion composed of a rapid effective stroke and a slower recovery stroke, while keeping the vibration frequency constant. The results demonstrate that the timing of bend initiation within the flagellar beat cycle can be controlled mechanically by changing the time point within the vibration cycle at which the micropipette changes its direction of motion. A switch in the sidedness of the asymmetric movement of the micropipette produces dramatic changes in the profiles of bend growth in the basal 5 microns of the flagellum but has almost no effect on the asymmetry or other parameters of bending in the mid- and distal regions of the flagellum. Our results suggest that elastic strain within the basal region of the flagellar structure may play a more significant role in the process of bend initiation than has been realized heretofore.
海胆精子鞭毛的运动参数可以通过对用微量移液器尖端吸力固定的精子头部施加各种周期性振动模式来进行机械操控。鞭毛的摆动频率很容易与外部施加的横向振动频率同步，并且鞭毛弯曲波的平面会使其自身适应移液器振动的平面（吉本斯等人，《细胞生物学杂志》101:270a，1985年；《自然》325:351 - 352，1987年）。在本研究中，我们通过以由快速有效冲程和较慢恢复冲程组成的横向锯齿状运动振动固定精子头部的微量移液器，同时保持振动频率恒定，来观察外部不对称力对鞭毛摆动参数的特定影响。结果表明，在鞭毛摆动周期内弯曲起始的时间可以通过改变微量移液器改变其运动方向的振动周期内的时间点来进行机械控制。微量移液器不对称运动的方向切换会在鞭毛基部5微米处的弯曲生长轮廓上产生显著变化，但对鞭毛中部和远端区域弯曲的不对称性或其他参数几乎没有影响。我们的结果表明，鞭毛结构基部区域内的弹性应变在弯曲起始过程中可能比迄今所认识到的发挥更重要的作用。
