In mammals, the 5-methylcytosine epigenetic mark is mostly located in transposable elements, which are repetitive intragenomic parasites. In this issue of Nature Aging, Gorbunova and colleagues show that 5-methylcytosine levels in certain LINE1 retrotransposon loci highly correlate with age and the incidence of certain pathologies. Thus, LINE1 (the only known transposable element family capable of autonomous jumping in the human genome) serves as a suitable DNA template for accurately determining age and predicting disease.
- Bernadette Hotzi
- Tibor Vellai