Speedy Sperm

From ejaculation to fertilisation, sperm cells embark on an adventure, moving along the walls of the uterus and cervix until they reach their prize: an egg cell in the oviduct. Not only do sperm have to travel a relatively huge distance to reach the egg, they also have to swim through fluids of variable speeds and thicknesses. Researchers set up an ‘assault course’, where, using a technique called microfluidics, they saw the travelling in action. They observed sperm wiggling in a spiral motion upstream, avoiding the centre of the tubes where flow was fastest. When exposed to thicker fluids, sperm turn and quickly readjust to the flow – seen here as an arc-shaped track. Sperm also grouped together, working collectively to swim faster, rather than in competition with each other. These observations provide new insights into the fertilisation process and could help with the design of more effective artificial insemination methods.

Written by Katie Panteli

Katie Panteli

Writer

Katie, a Warwick Biomed graduate, works for a science-publishing house in London with some of the world's most respected scientific minds. She's most interested in human biology, anything and everything that makes us tick.

• Video by Raymond Goldstein and colleagues
• University of Cambridge, UK
• Originally published under a Creative Commons Licence (BY 4.0)
• Research published in eLife, May 2014