Restoring Power

Mitochondria provide most of the chemical energy needed to run a cell, and to do so they must function efficiently. To maintain proper function, defective mitochondria are routinely degraded and replaced – either wholly or partially – by various pathways. One recently discovered pathway, for instance, specifically disposes of damaged mitochondrial DNA (mtDNA). The pathway involves an intracellular trafficking complex called the retromer, which transports damaged mtDNA to lysosomes – the cell’s garbage disposal units. The two fly larvae pictured are both genetically prone to excessive mtDNA damage, but while the build-up of damage is clear in the top larva – indicated by the dark spots representing tissue stress –such damage is dealt with in the bottom one thanks to increased expression of a retromer component. Since mitochondrial dysfunction underlies many human diseases, it’s possible that boosting retromer activity might be a way to restore mitochondrial energy production and thus a patient’s health.

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 Parisa Kakanj and Mari Bonse, and colleagues
• Institute of Genetics and Institute of Physiology, University Clinics and Faculty of Medicine, University of Cologne, Cologne, Germany
• Image contributed by Parisa Kakanj and published in the article with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in Science Advances, April 2025