Medical Research Council - London Institute of Medical Sciences

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Observing the mechanisms of success for sperm during fertilisation

18 January 2021

The Winning Tail

Millions embark on an epic journey, but only one makes it to the end. The race between countless sperm to fertilise an egg and kick-start the creation of a new life is a process of elimination, ensuring only one racer reaches the finish line. Lots of what we know about this competition comes from laboratory experiments, but real-world conditions are hard to replicate. A new study has visualised in 3D the reproductive tracts of female mice to provide a front row view. It revealed that a molecular channel in the tail of sperm, called CatSper1 (red), remains intact in sperm that make it to passages close to the egg (left and centre), but is degraded in those that fall early on (right). The status of this propelling structure could be a factor in selecting the finest sperm, which might point towards new targets for contraception or fertility treatments.

Written by Anthony Lewis

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