Modeling the Locomotion of the African Trypanosome

大自然为微生物提供了大量巧妙的解决方案，使它们能够在不使用惯性的情况下在流体环境中移动。开发的策略不仅在生物学上有意义，而且在医学和技术应用中也有意义。微生物非洲锥虫借助一种被称为鞭毛的跳动细丝游动，这种细丝牢固地附着在细长的细胞体上。最近有强有力的实验证据表明，由游动引发的液体流动与锥虫逃避免疫系统的能力密切相关。由于锥虫是导致人类昏睡病的原因，因此人们对研究该生物体生命周期的所有细节产生了极大的兴趣。在前两年的这个项目中，我们已经开发了一个模型，非洲锥虫，包括直线和螺旋附着的驱动鞭毛的组合。与模型锥虫，我们能够模拟现实的游泳模式和运动在狭窄的微通道通过处理流体环境的帮助下，多粒子碰撞动力学的介观方法。在剩下的第三年里，我们计划研究锥虫在不同实验条件下的行为。特别是，我们将研究在粘弹性环境中的运动，这是研究充满血细胞的血管的第一种方法。最后，我们还旨在首次研究锥虫的集体运动。

Nature provides microorganisms with a wealth of ingenious solutions thatenable them to move through a fluid environment without using inertia.The strategies developed have relevance not only in biology, but alsoin medical and technological applications. The microorganism African trypanosome swims with the help of a beating filament, known as flagellum, that is firmly attached to the elongated cell body.There has recently been strong experimental evidence that the fluid flowinitiated by swimming is intimately linked with the ability of the trypanosome to evade the immune system. Since the trypanosome is the cause of sleeping sickness in humans, there is immense interest in investigating all details of the organism's lifecycle. In the preceding two years of this project, we have developed a model for the African trypanosome including a combination of straight and helical attachment of the actuating flagellum. With the model trypanosome we are able to simulate realistic swimming patterns and locomotion in narrow microchannels by treating the fluid environment with the help of the mesoscopic method of multi-particle collision dynamics. In the remaining third year we plan tostudy the behavior of the trypanosome under different experimental situations.In particular, we will look at locomotion in a model viscoelastic environment whichserves as a first approach for blood vessels filled with blood cells. Finally, we also aim at a first study of the collective motion of trypanosomes.