Lighting a Fuse

Proteins are tiny biological machines that do vital jobs in our cells and tissues. They’re made to very precise instructions in a sort of 'protein factory' called the ribosome. But the ribosomes themselves are made in the nucleolus – a tiny organ, or organelle, that is fairly unusual. Nucleoli don’t have membranes, leaving their wobbly structures more influenced by the stresses and strains inside cells. Here researchers investigate how these forces affect several gloopy nucleoli that have fused together (highlighted in purple). Denser, more viscoelastic, regions inside (green) also merge, although more slowly. What does it mean that these vital organelles slosh around our cells? The team are investigating other factors that affect the fluidity of the nucleolus, which may have huge implications for our understanding of cellular life in health and disease.

Written by John Ankers

John Ankers

Writer

A former researcher in systems biology, John is now an online biology tutor and professional coach supporting the wellbeing of scientists and NHS professionals. He's writing, too, of course.

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• Video from work by Holly H. Cheng and colleagues
• Department of Molecular Biology, Princeton University, Princeton, NJ, USA
• Video originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in Proceedings of the National Academy of Science (PNAS), May 2025