Controlled Explosion

Like water from a firefighter’s hose, sperm must be sent forward with sufficient vigour to reach its target. But how this jet is propelled isn't fully understood. A new study used live imaging in mice to watch the physical and molecular changes that happen in the crucial moments. They found that sperm transport is the result of both muscle contraction (squeezing the tubes), and molecular signalling. The team identified different signalling roles working in concert. Signalling proteins called ROCK and PKA help power the muscle contraction, while another, ERK, responds to flow to open and remodel a valve-like section at the end of the vas deferens (pictured, ROCK, PKA, and ERK activity shown in red left to right before (top) and after (bottom) contraction was experimentally stimulated). The findings have broad relevance to how tubular organs coordinate fluid movement, and could ultimately explain aspects of male infertility.

Written by Anthony Lewis

Anthony Lewis

Writer

Ant was the web editor in the early days of BPoD, and has since worked with the UK’s top science organisations as a writer and multimedia producer. He now splits his time between freelance work and managing multimedia at The Lancet.

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• Image from work by Nicole Ng Shu Ying and colleagues
• Mechanobiology Institute, National University of Singapore, Singapore, Singapore
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in bioRxiv, May 2026 (not peer reviewed)