Shingyoji C, Gibbons I R, Murakami A, Takahashi K
Zoological Institute, Faculty of Science, University of Tokyo, Japan.
J Exp Biol. 1991 Mar;156:63-80. doi: 10.1242/jeb.156.1.63.
The heads of live spermatozoa of the sea urchin Hemicentrotus pulcherrimus were held by suction in the tip of a micropipette mounted on a piezoelectric device and vibrated either laterally or axially with respect to the head axis. Within certain ranges of frequency and amplitude, lateral vibration of the pipette brought about a stable rhythmic beating of the flagella in the plane of vibration, with the beat frequency synchronized to the frequency of vibration [Gibbons et al. (1987), Nature 325, 351-352]. The sperm flagella, with an average natural beat frequency of 48 Hz, showed stable beating synchronized to the pipette vibration over a range of 35-90 Hz when the amplitude of vibration was about 20 microns or greater. Vibration frequencies below this range caused instability of the beat plane, often associated with irregularities in beat frequency. Frequencies above about 90 Hz caused irregular asymmetrical flagellar beating with a marked decrease in amplitude of the propagated bends and a skewing of the flagellar axis towards one side; the flagella often stopped in a cane shape. In flagella that were beating stably under imposed vibration, the wavelength was reduced at higher frequencies and increased at lower frequencies. When the beat frequency was equal to or lower than the natural beat frequency, the apparent time-averaged sliding velocity of axonemal microtubules, obtained as twice the product of frequency and bend angle, decreased with beat frequency in both the proximal and distal regions of the flagella. However, at vibration frequencies above the natural beat frequency, the sliding velocity increased with frequency only in the proximal region of the flagellum and remained essentially unchanged in more distal regions. This apparent limit to the velocity of sliding in the distal region may represent an inherent limit in the intrinsic velocity of active sliding, while the faster sliding observed in the proximal region may be a result of passive sliding or elastic distortion of the microtubules induced by the additional energy supplied by the vibrating pipette. Axial vibration with frequencies either close to or twice the natural beat frequency induced cyclic changes in the waveform, compressing and expanding the bends in the proximal region, but did not affect bends in the distal region or alter the beat frequency.
将海胆光棘球海胆（Hemicentrotus pulcherrimus）活精子的头部通过吸力固定在安装在压电装置上的微量移液器尖端，并相对于头部轴线进行横向或轴向振动。在一定的频率和振幅范围内，移液器的横向振动会使鞭毛在振动平面内产生稳定的节律性摆动，摆动频率与振动频率同步[吉本斯等人（1987年），《自然》325卷，351 - 352页]。精子鞭毛的平均自然摆动频率为48赫兹，当振动幅度约为20微米或更大时，在35 - 90赫兹范围内显示出与移液器振动同步的稳定摆动。低于此范围的振动频率会导致摆动平面不稳定，通常伴有摆动频率的不规则性。高于约90赫兹的频率会导致鞭毛不规则的不对称摆动，传播弯曲的幅度明显减小，鞭毛轴偏向一侧；鞭毛常常呈手杖状停止摆动。在施加振动下稳定摆动的鞭毛中，波长在较高频率下减小，在较低频率下增加。当摆动频率等于或低于自然摆动频率时，轴丝微管的表观时间平均滑动速度（通过频率和弯曲角度乘积的两倍获得）在鞭毛的近端和远端区域均随摆动频率降低。然而，在高于自然摆动频率的振动频率下，滑动速度仅在鞭毛的近端区域随频率增加，而在更远端区域基本保持不变。远端区域滑动速度的这种明显限制可能代表主动滑动内在速度的固有极限，而在近端区域观察到的更快滑动可能是由振动移液器提供的额外能量引起的微管被动滑动或弹性变形的结果。频率接近或为自然摆动频率两倍的轴向振动会引起波形的周期性变化，压缩和扩展近端区域的弯曲，但不影响远端区域的弯曲或改变摆动频率。
