Gibbons I R, Gibbons B H
J Muscle Res Cell Motil. 1980 Mar;1(1):31-59. doi: 10.1007/BF00711924.
Flagellar waveforms have been studied during the stopping and starting transients of light-induced, Ca2+-mediated, intermittent swimming of live sperm of the sea urchin Tripneustes gratilla. Tracings of successive frames of movie film made at about 200 frames s-1 were used to determine the bend propagation velocity, beat frequency, and bend angles during three stopping and four starting transients chosen as representative of the range of variation among sperm in the preparations. A stopping transient begins with a transitional stage in which the asymmetry of the bending waves increases steadily over 2-6 beat cycles (40-120 ms), with the angles of successive fully developed principal bends increasing and those of reverse bends decreasing. This is followed by a blocked stage, lasting one beat cycle (20 ms), in which a principal bend becomes arrested and then decays in the mid-region of the flagellum. The next principal bend forms but remains unpropagated at the base, apparently because no following reverse bend is initiated, and the flagellum becomes quiescent. Quiescent flagella have a characteristic, highly asymmetric waveform consisting of a sharp principal bend of about 3.2 rad at the basal end, a nearly straight mid-region and a gentle principal bend of about 0.4 rad near the tip. After a quiescent period of 0.2-2 s, motility is resumed with the initiation of a new reverse bend at the base. This bend and the proximal principal bend remaining from quiescence begin to propagate but they decay before passing more than halfway along the flagellum. In this blocked stage of the starting transient, which lasts 1-15 beat cycles (20-300 ms), successive principal and reverse bends are propagated progressively further along the flagellum but they decay before reaching the tip and the asymmetry remains at the high value characteristic of quiescence. The first propagation of a principal bend to the tip marks the beginning of the transitional stage of the transient, during which the asymmetry of the bending waves gradually decreases until after 2-5 beat cycles (40-100 ms) it reaches the value characteristic of steady-state beating. In both stopping and starting flagella the beat frequency and the mean of the principal and reverse bend angles remain constant throughout the transient (except for the beat cycle immediately pre- or post-quiescence), indicating that they are regulated by mechanisms almost completely independent of that regulating wave symmetry. The bend propagation velocity remains constant during stopping transients but it is diminished during the blocked stage of starting transients, indicating that the bend velocity, and hence the wavelength, can be altered by changes in the internal resistance to bend propagation.
在光诱导、Ca2+介导的海胆瘤海胆活精子间歇性游动的停止和启动瞬态过程中，对鞭毛波形进行了研究。以大约200帧/秒拍摄的电影胶片连续帧的追踪结果，用于确定在三个停止瞬态和四个启动瞬态过程中的弯曲传播速度、拍频和弯曲角度，这些瞬态被选为代表制剂中精子变化范围的典型例子。一个停止瞬态始于一个过渡阶段，在此阶段弯曲波的不对称性在2 - 6个拍周期（40 - 120毫秒）内稳步增加，相继完全发育的主弯曲角度增加，反向弯曲角度减小。接下来是一个阻塞阶段，持续一个拍周期（20毫秒），在此期间一个主弯曲在鞭毛中部停止然后衰减。下一个主弯曲形成但在基部未传播，显然是因为没有引发后续的反向弯曲，鞭毛变得静止。静止的鞭毛具有特征性的、高度不对称的波形，由基部约3.2弧度的尖锐主弯曲、几乎笔直的中部区域和靠近顶端约0.4弧度的平缓主弯曲组成。在0.2 - 2秒的静止期后，随着基部新的反向弯曲的启动，运动恢复。这个弯曲和静止时剩余的近端主弯曲开始传播，但在沿着鞭毛传播超过一半之前就衰减了。在启动瞬态的这个阻塞阶段，持续1 - 15个拍周期（20 - 300毫秒），相继的主弯曲和反向弯曲沿着鞭毛逐渐传播得更远，但在到达顶端之前就衰减了，不对称性保持在静止时的高值特征。主弯曲首次传播到顶端标志着瞬态过渡阶段的开始，在此期间弯曲波的不对称性逐渐减小，直到在2 - 5个拍周期（40 - 100毫秒）后达到稳态跳动的特征值。在停止和启动的鞭毛中，拍频以及主弯曲和反向弯曲角度的平均值在整个瞬态过程中保持恒定（除了紧接静止之前或之后的拍周期），这表明它们是由几乎完全独立于调节波对称性的机制调节的。弯曲传播速度在停止瞬态期间保持恒定，但在启动瞬态的阻塞阶段减小，这表明弯曲速度以及波长可以通过弯曲传播内部阻力的变化而改变。
