New Gene Clocks Predict Biological Age and Time to Death Across Mammal Species

A Universal Signature of Ageing

An international team of researchers has built a new kind of biological clock that can estimate how old your body really is and even predict how much time you have left, using the activity of your genes. Publishing their findings in Nature, the scientists found that the molecular changes driving ageing are remarkably consistent across very different mammals, including mice, rats, macaques, and humans.

The study, led by Alexander Tyshkovskiy of Brigham and Women's Hospital and Harvard Medical School, analysed more than 11,000 transcriptomes drawn from over 25 tissues across the four species. Rather than looking at the genes you are born with, the team measured gene expression, which is how active those genes are at any given moment. They discovered that the same ageing-associated shifts in gene activity appear again and again, regardless of tissue type or species.

What Ages Us, and What Declines

The pattern that emerged tells a clear story. Genes tied to inflammation, immune activation, and cellular stress tend to ramp up as we get older, while genes responsible for mitochondrial energy production and wound healing quietly wind down. In other words, the body grows noisier and more inflamed even as its repair and energy systems lose power.

Because these signals were so consistent, the researchers were able to turn them into molecular clocks capable of estimating biological age and predicting expected mortality. In humans, the clocks predicted time to death from any cause among participants in a large heart-health study, with accuracy comparable to second-generation epigenetic clocks. As Tyshkovskiy put it, the same genes are associated with ageing in, for example, the liver and heart of both rats and humans, suggesting that ageing is a deeply systemic process.

A Faster Tool for Longevity Science

The clocks were also trained on data from rodents given dozens of genetic, dietary, and pharmacological interventions known to influence ageing and lifespan, allowing the models to capture treatments that sped up or slowed down biological decline. That ability is what excites longevity researchers most.

David Sinclair, a prominent ageing researcher, praised the work, noting that the team developed transcriptomic clocks that do not just estimate age but measure the progressive loss of cellular function and predict biological decline and mortality risk across mammals. Unlike earlier epigenetic clocks based on DNA methylation, these transcriptomic clocks directly read gene activity, potentially offering a more functional readout of the processes that drive ageing. Researchers say this could dramatically speed up the search for anti-ageing therapies, giving scientists a quicker way to tell whether an experimental treatment is genuinely slowing ageing at the molecular level, rather than waiting years to see its effect on lifespan.