Brennen C
J Mechanochem Cell Motil. 1976 Mar;3(3):207-17.
Theoretical hydrodynamic analyses of the locomotion of flagellates with mastigonemes are presented and particular comparison is made within experimental data on Ochromonas malhamensis. The first part of the paper analyses locomotion assuming the mastigonemes are rigid and maintain a fixed and normal position relative to the flagellum. The predicted propulsive velocity of 60 mum/sec for Ochromonas agrees well with the observed values of 55-60 mum/sec. It is shown that the propulsive system of Ochromonas represents a compromise between the need for efficient rectilinear propulsion and the need to manoeuvre and accelerate. The effect of rigid mastigonemes which are maintained at non-zero angles to the flagellar normal is also calculated and demonstrates a significant degradation of performance when this angle is greater than about 10 degrees. The latter part of the paper investigates the more complex but more realistic situation in which the mastigonemes flex during the motion according to the instantaneous hydrodynamic forces imposed upon them. The cyclical flexing history of a mastigoneme with passage of a flagellar wave and the consequent velocity of propulsion are obtained for a variety of geometric configurations and structural mastigoneme stiffnesses. It is demonstrated that there exists a relatively small transition range in the values of mastigoneme flexibility below which the mastigonemes are essentially rigid and above which they become totally ineffective hydrodynamically so that the flagellum can be regarded as essentially smooth. Since the transition value of the modulus of elasticity is about 5 dynes/mum2 (or stiffness of 3.5 X 10(-16) dyne cm2) for the mastigonemes of Ochromonas it would appear that the actual value must be in excess of this. Comparison is made with the structural properties of the micro-tubules in eukaryote cilia and flagella and with prokaryote flagella. The latter comparison suggests that the mastigonemes of Ochromonas are just rigid enough to produce the observed propulsive effect.
本文对具茸鞭型鞭毛的鞭毛虫运动进行了理论流体动力学分析，并与关于玛氏赭球虫的实验数据进行了详细比较。论文的第一部分在假设茸鞭毛为刚性且相对于鞭毛保持固定的正常位置的条件下分析了运动。预测玛氏赭球虫的推进速度为60微米/秒，这与观察到的55 - 60微米/秒的值非常吻合。结果表明，玛氏赭球虫的推进系统是在高效直线推进需求与操纵和加速需求之间的一种折衷。还计算了与鞭毛法线保持非零角度的刚性茸鞭毛的影响，结果表明当这个角度大于约10度时，性能会显著下降。论文的后半部分研究了更复杂但更现实的情况，即茸鞭毛在运动过程中会根据施加在它们身上的瞬时流体动力而弯曲。对于各种几何构型和茸鞭毛结构刚度，得到了茸鞭毛随鞭毛波通过的周期性弯曲历程以及相应的推进速度。结果表明，茸鞭毛柔韧性值存在一个相对较小的转变范围，在此范围以下茸鞭毛基本是刚性的，而在此范围以上它们在流体动力学上变得完全无效，从而可以认为鞭毛基本是光滑的。由于玛氏赭球虫茸鞭毛的弹性模量转变值约为5达因/微米²（或刚度为3.5×10⁻¹⁶达因·厘米²），实际值似乎必须超过这个值。文中还将其与真核生物纤毛和鞭毛以及原核生物鞭毛的结构特性进行了比较。后一种比较表明，玛氏赭球虫的茸鞭毛刚好足够刚性以产生观察到的推进效果。
