Between the Gaps

To keep a pesky animal out of your garden, you just need to make sure the gaps between your fence posts are narrower than the animal. In our bodies, cells similarly create barriers to keep out unwanted invaders, but some pests are particularly crafty. Trypanosoma brucei is a parasite that causes African Sleeping Sickness, and penetrates deep into our tissues. New research has found how it sneaks in so easily. It can deform its body and squeeze through gaps smaller than its diameter. Its movement and shape is driven by a flagellum – a long propellor-like tail – and researchers engineered parasites with modified flagella to see how they work (bottom two video strips, compared to normal parasites, top). Without their natural flagella they struggled to make progress through small gaps. Clearly flagella are crucial to the parasite’s penetrative power, so trimming the tail might be a way of slowing it down.

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/video from work by Sun and colleagues
• Mechanobiology Institute, National University of Singapore, Singapore
• Video originally published under a Creative Commons (CC BY-NC-ND 4.0) attribution
• Published in PNAS, June 2018