Hear Hair

Any teacher knows that if the children aren’t all lined up correctly, they won’t listen properly. So too for tiny bundles of hairs in the ear, which must align with a central projection, the kinocilium. Deafness can result from dysfunction of proteins that form links between the bundles and the kinocilium, so, with particular focus on one protein PCDH15-CD2, researchers genetically engineered mice lacking the corresponding genes and observed the effects on hair bundles (pictured in such a mouse’s ear balance centre, the saccule). The proteins appear at the base of the kinocilium even before physical links between these and the bundles form, and without them bundles were disordered or fragmented, explaining the genes’ role in deafness and balance disorders. Hair cells’ intrinsic sense of direction (polarity) was warped without PCDH15-CD2, but restoring it early enough helped them back on track, which could have implications for gene therapy or regeneration strategies for sensory hair cells.

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 Raman Kaushik and colleagues
• National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, Karnataka, India
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in PLOS Genetics, August 2025