Overview
- Researchers used microchannel assays to show newborn neurons form widespread DNA double-strand breaks as they squeeze through confined spaces, and the breaks largely disappear after the cells finish migrating.
- The team traced the damage to Topoisomerase IIβ becoming mechanically trapped while cutting DNA, creating persistent breaks that require repair.
- Most migration-induced breaks are sealed within about 24 hours by the fast repair pathway non-homologous end joining, with Ligase 4 performing the final ligation step.
- Mice engineered to lack Ligase 4 in newly formed cerebellar neurons developed mild, progressive balance problems in early adulthood, showing that incomplete repair can cause lasting functional effects.
- The work reframes neuronal genome stability as an active balance between routine mechanical damage and prompt repair, raising tests for lasting mutational signatures and possible links to neurodevelopmental or neurodegenerative disease.