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Cell biology

DNA methylation

DEDNA-Methylierung

DNA methylation is one of the main ways your cells control which genes are switched on, without changing the DNA code itself. Enzymes called DNA methyltransferases stick small chemical tags (methyl groups) onto your DNA, mostly at spots called CpG sites. This tells genes when to stay quiet, helps inactivate one X chromosome in females, and keeps the genome stable. The pattern shifts in predictable ways as you age, which is exactly what epigenetic clocks like Horvath's read to estimate biological age. When methylation goes wrong, it can drive cancer, weaken the immune system, and feed the general epigenetic drift of aging.

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Sources

  1. Smith & Meissner. (2013). DNA methylation: roles in mammalian development. *Nature Reviews Genetics*doi:10.1038/nrg3354
  2. Horvath. (2013). DNA methylation age of human tissues and cell types. *Genome Biology*doi:10.1186/gb-2013-14-10-r115