Modeling the locomotion of the African trypanosome using multi-particle collision dynamics
Modeling the locomotion of the African trypanosome using multi-particle collision dynamics
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DOI：
10.1088/1367-2630/14/8/085012
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发表时间：
2012-08-17
影响因子：
3.3
通讯作者：
Stark, Holger
中科院分区：
文献类型：
--
作者：
Babu, Sujin B.;Stark, Holger
非洲锥虫是一种鞭毛微生物，能引起人类和动物的致命昏睡病。我们研究了一个模型锥虫的运动通过建模的纺锤形细胞体使用附加弯曲刚度顶点的弹性网络。紧紧附着在模型细胞体上的鞭毛或直或螺旋。弯曲波沿着鞭毛传播并推动锥虫在其粘性环境中前进，我们用多粒子碰撞动力学方法模拟了这一过程。模型细胞体在静态弯曲波作用下的松弛动力学揭示了弹性流体力学中的精子数作为相关参数。螺旋附着的鞭毛的典型细胞体构象与实验观察相似。我们表明，游泳速度是弯曲波角频率的根，这让人想起了对附着在大粘性载荷上的驱动细长杆的预测。当一个几何图形的游泳速度与精子数量相对应时，它会在一条主曲线上崩塌。实验中观察到，螺旋附着的鞭毛导致模型锥虫沿其长轴进行螺旋游动和旋转。模拟的游泳速度与实验值吻合。
The African trypanosome is a single flagellated micro-organism that causes the deadly sleeping sickness in humans and animals. We study the locomotion of a model trypanosome by modeling the spindle-shaped cell body using an elastic network of vertices with additional bending rigidity. The flagellum firmly attached to the model cell body is either straight or helical. A bending wave propagates along the flagellum and pushes the trypanosome forward in its viscous environment, which we simulate with the method of multiparticle collision dynamics. The relaxation dynamics of the model cell body due to a static bending wave reveals the sperm number from elastohydrodynamics as the relevant parameter. Characteristic cell body conformations for the helically attached flagellum resemble experimental observations. We show that the swimming velocity scales as the root of the angular frequency of the bending wave reminiscent of predictions for an actuated slender rod attached to a large viscous load. The swimming velocity for one geometry collapses on a single master curve when plotted versus the sperm number. The helically attached flagellum leads to a helical swimming path and a rotation of the model trypanosome about its long axis as observed in experiments. The simulated swimming velocity agrees with the experimental value.