28/01/2026
Epigenetics studies how behaviors and environment can cause changes that affect the way your genes work, without altering the DNA sequence itself, acting like switches to turn genes "on" or "off". These modifications, involving chemical tags on DNA and proteins, can influence cell function and can even be passed down through generations, explaining differences between identical twins and how lifestyle factors like diet, stress, or drug use impact health. Key mechanisms include DNA methylation and histone modification, which control access to genes, leading to diverse cell types from the same genetic blueprint.
Key Concepts
Gene Expression Control: Epigenetics provides instructions for when and how genes are used, allowing a brain cell to be different from a skin cell despite having the same DNA.
No DNA Sequence Change: Unlike genetic mutations, epigenetic changes add to the DNA, altering its expression but not the underlying code (A, T, C, G).
Environmental Influence: Diet, stress, toxins, and physical activity can trigger epigenetic modifications.
Heritability: Some epigenetic marks can be inherited, potentially affecting future generations.
Main Mechanisms
DNA Methylation: Adding methyl groups to DNA, often silencing genes.
Histone Modification: Altering histone proteins around which DNA is wrapped, making genes more or less accessible.
Chromatin Remodeling: Changing how tightly DNA is packed.
Examples & Implications
Cell Differentiation: Determines whether a cell becomes a nerve cell or a muscle cell.
Disease: Can be linked to cancer, addiction (due to drug/alcohol effects), and brain disorders like PTSD.
Aging: The "epigenetic clock" measures biological age by tracking DNA methylation patterns.
Identical Twins: Explains slight differences in appearance and health between identical twins.