# Chromatin

Chromatin is the bundle of DNA, histone proteins, and other proteins that packs your genome into the nucleus. Its basic unit is the nucleosome. It can be packed tight (as 'heterochromatin') or held loose (as 'euchromatin'), which controls which genes are open for reading. This packaging protects your genome's stability and a cell's identity. Losing heterochromatin, and a messy chromatin layout, are recognized hallmarks of aging and feed cellular dysfunction.

## Sources

- Benayoun BA, Pollina EA, Brunet A. (2015). Epigenetic regulation of ageing: linking environmental inputs to genomic stability. Nature Reviews Molecular Cell Biology. https://doi.org/10.1038/nrm4048
- López-Otín et al.. (2023). Hallmarks of aging: An expanding universe. Cell. https://doi.org/10.1016/j.cell.2022.11.001

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_Canonical: https://longevity-switzerland.com/en/glossary/chromatin · Part of Longevity Cities · Updated 2026-06-22_