Mechanobiology of mammalian sperms

为了探索机械刺激在模拟输卵管受精的微流体环境中的作用，我们研究了运动精子胞间Ca浓度（[Ca^<2+>]i）与剪切应力（SS）的关系，并探讨了机械刺激的分子机制。我们发现在流动中，运动精子头部的[Ca^<2+>]i高于非运动精子头部。能处理Ca^<2+>的运动精子的头部方向与流体流动方向明显相反，而非运动精子的头部与流动方向的角度呈双峰分布。当流体流速增加时，荧光强度会增加一秒钟。在流速和SS变化中观察到轻微的荧光变化。基于本研究，我们提出头部细胞内钙浓度的变化可能是SS的反应，但通过改变流速引起的细胞内钙浓度的变化可能是轻微的二级事件。

To find the role of mechanical stimuli for fertilization in microfluidic environment that can mimic that of the oviduct, we investigated the relationship between interacellular Ca concentration ([Ca^<2+>]i) and shear-stress (SS) in motile sperms and discussed the molecular mechanism of the mechano-sensing. We found that the [Ca^<2+>]i in the head of a motile sperm is higher than that in the head of a non-motile sperm in flow. The directions of the heads of motile sperms that can handle Ca^<2+> were against the fluid flow direction significantly, while the distribution of the angles between non-motile sperms and flow direction is bimodal. When the fluid velocity increased, an increase in the fluorescent intensity was observed for a second. Slight fluorescent change was observed in the fluid velocity and SS change. Our proposal based on this study is that intracellular calcium concentration changes in the head might be responses of SS, but the intracellular calcium concentration changes by altering flow velocity would be slight and second-scale events.