Sperm's Swimming System

Sperms are simple structures. They consist of a head, containing the genetic payload, and a tail that beats furiously to power the cell to its destination – the egg. The tail is packed with scaffold structures called microtubules that move together in a precisely coordinated fashion to ensure the sperm swims in a straight line (top). And recent research is uncovering the molecular requirements for this precision. Scientists have found that tubulin – the primary component of microtubules – undergoes a molecular modification called glycylation that’s essential for associated motor proteins to power the coordinated movements. Interrupting the glycylation process in mice caused the animals’ sperms to swim haphazardly – such as at tangents (bottom), or round in circles (middle) – and reduced fertility as a result. Since human sperms are similar to those of mice, the findings could proffer insights into male infertility caused by wayward swimmers, as well as ways to fix it.

Written by Ruth Williams

Ruth Williams

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Ruth is a freelance science journalist based in the US. She's a regular correspondent for The Scientist, and her work has appeared in The Lancet, Nature, Scientific American Mind, BBC Focus and elsewhere. Twitter @rooph

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• Image from work by Sudarshan Gadadhar and colleagues
• Institut Curie, Université PSL, CNRS UMR3348, Orsay, France
• Image copyright held by the original authors
• Research published in Science, January 2021