Department of Food Science and Technology, Cornell University, Ithaca, NY 14853, USA.
The Ronald O. Perelman and Claudia Cohen Center for Reproductive Medicine, Weill Cornell Medicine, New York, NY 10021, USA.
Sci Adv. 2019 Feb 13;5(2):eaav2111. doi: 10.1126/sciadv.aav2111. eCollection 2019 Feb.
Investigating sperm locomotion in the presence of external fluid flow and geometries simulating the female reproductive tract can lead to a better understanding of sperm motion during fertilization. Using a microfluidic device featuring a stricture that simulates the fluid mechanical properties of narrow junctions inside the female reproductive tract, we documented the gate-like role played by the stricture in preventing sperm with motilities below a certain threshold from advancing through the stricture to the other side (i.e., fertilization site). All the slower sperm accumulate below (i.e., in front of) the stricture and swim in a butterfly-shaped path between the channel walls, thus maintaining the potential for penetrating the stricture and ultimately advancing toward the fertilization site. Accumulation below the stricture occurs in a hierarchical manner so that dense concentrations of sperm with higher velocities remain closer to the stricture, with more sparsely distributed arrays of lower-velocity sperm lagging behind.
研究精子在外部流体流动和模拟女性生殖道的几何形状下的运动，可以帮助我们更好地理解精子在受精过程中的运动。我们使用一种微流控装置，其中包含一个狭窄的结构，模拟了女性生殖道内部狭窄连接处的流体力学特性，记录了狭窄结构在阻止低于一定阈值的游动精子穿过狭窄结构到达另一侧（即受精部位）方面的门控作用。所有游动速度较慢的精子都在狭窄结构下方（即前方）聚集，并在通道壁之间呈蝴蝶形路径游动，从而保持穿透狭窄结构并最终向受精部位推进的潜力。在狭窄结构下方的聚集是分层进行的，因此速度较高的密集精子浓度更接近狭窄结构，而速度较低的稀疏分布的精子则落后。
