精蟲受到卵細胞之化學吸引而聚集

幾萬隻精蟲於同房後進入子宮腔，
可能僅有數百隻精蟲到達輸精管末端壺腹部位之卵子處，
卵子隱藏於輸精管末端壺腹部位之輸精管內壁皺摺，
精蟲可能受到卵子細胞之化學吸引才能找到卵子

http://www.pnas.org/content/109/21/8007.full

Human spermatozoa migration in microchannels reveals boundary-following navigation

1. Petr Denissenkoa,b,1, 
2. Vasily Kantslerc, 
3. David J. Smitha,b,d, and 
4. Jackson Kirkman-Brownb,e

+Author Affiliations

1. aSchool of Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom;
2. bCentre for Human Reproductive Science, Birmingham Women’s National Health Service Foundation Trust, Mindelsohn Way, Birmingham B15 2TG, United Kingdom;
3. cDepartment of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, United Kingdom;
4. dSchool of Mathematics, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom; and
5. eSchool of Clinical and Experimental Medicine, University of Birmingham, Edgbaston, Birmingham, B15 2TT United Kingdom

1. Edited by David A. Weitz, Harvard University, Cambridge, MA, and approved April 3, 2012 (received for review February 22, 2012)

 

Next Section

Abstract

The migratory abilities of motile human spermatozoa in vivo are essential for natural fertility, but it remains a mystery what properties distinguish the tens of cells which find an egg from the millions of cells ejaculated. To reach the site of fertilization, sperm must traverse narrow and convoluted channels, filled with viscous fluids. To elucidate individual and group behaviors that may occur in the complex three-dimensional female tract environment, we examine the behavior of migrating sperm in assorted microchannel geometries. Cells rarely swim in the central part of the channel cross-section, instead traveling along the intersection of the channel walls (“channel corners”). When the channel turns sharply, cells leave the corner, continuing ahead until hitting the opposite wall of the channel, with a distribution of departure angles, the latter being modulated by fluid viscosity. If the channel bend is smooth, cells depart from the inner wall when the curvature radius is less than a threshold value close to 150 μm. Specific wall shapes are able to preferentially direct motile cells. As a consequence of swimming along the corners, the domain occupied by cells becomes essentially one-dimensional, leading to frequent collisions, and needs to be accounted for when modeling the behavior of populations of migratory cells and considering how sperm populate and navigate the female tract. The combined effect of viscosity and three-dimensional architecture should be accounted for in future in vitro studies of sperm chemoattraction.