Epigenetics

Definition

Epigenetics refers to heritable, chromatin-based regulation of gene expression that does not alter the underlying DNA sequence. These modifications shape which genes are active or silent and help stabilize cellular identity across divisions.[1][2]

Core Mechanisms

Core mechanisms include DNA methylation, histone post-translational modifications, and ATP-dependent chromatin remodeling. These layers integrate developmental and environmental signals to regulate transcriptional programs and maintain cell-type specificity.[3][4][5]

Relevance to Ageing

Epigenetic patterns shift with age and environmental exposure, contributing to altered gene regulation and genomic stability. These age-related changes underpin DNA methylation "clocks" used to estimate biological age and are recognized as a hallmark of ageing-related change.[6][7][8]

References

1. Bird, A. (2007). Perceptions of epigenetics. https://doi.org/10.1038/nature05913
2. Berger, S. L., et al. (2009). An operational definition of epigenetics. https://doi.org/10.1101/gad.1787609
3. Allis, C. D., & Jenuwein, T. (2016). The molecular hallmarks of epigenetic control. https://doi.org/10.1038/nrg.2016.59
4. Kouzarides, T. (2007). Chromatin modifications and their function. https://doi.org/10.1016/j.cell.2007.02.005
5. Portela, A., & Esteller, M. (2010). Epigenetic modifications and human disease. https://doi.org/10.1038/nbt.1684
6. Lopez-Otin, C., et al. (2013). The hallmarks of aging. https://doi.org/10.1016/j.cell.2013.05.039
7. Benayoun, B. A., et al. (2016). Epigenetic regulation of ageing: linking environmental inputs to genomic stability. https://doi.org/10.1038/nrm.2015.16
8. Horvath, S. (2013). DNA methylation age of human tissues and cell types. https://doi.org/10.1186/gb-2013-14-10-r115