How Old Is That Polar Bear? The Answer Is in Its Blood

Soon the polar bears will be taking rapamycin :grinning:

On Thursday, an international team of scientists published a study in the journal Nature Aging showing that epigenetic clocks tick inside 185 different species of mammals, including people. That study, as well as a related one published on Thursday in the journal Science, suggest that the epigenetic clock starts ticking shortly after an organism’s fertilization, and its speed determines how long a species can live.

The research has shown, for example, that smoking, obesity and drinking can add years to the epigenetic clock, and that this acceleration in biological age predicts a greater risk of death.

Full NYT Article:

Related Open Access Paper:

Universal DNA methylation age across mammalian tissues

Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, are near genes implicated in mammalian development, cancer, obesity and longevity. Our findings offer new evidence suggesting that aging is evolutionarily conserved and intertwined with developmental processes across all mammals.

DNA methylation networks underlying mammalian traits

DNA methylation installs a methyl group to cytosine, placing an epigenetic mark that regulates gene expression. Comparative epigenomics combines epigenetic signatures with phylogenetic relationships to understand species characteristics. Haghani et al . evaluated methylation levels in highly conserved DNA sequences, profiling ~15,000 samples across 348 mammalian species (see the Perspective by de Mendoza). Phylogenetic trees suggest that the divergence of DNA methylation profiles closely mirrors genetic evolution. Species with longer maximum life spans have developed tidier methylation patterns within the genome, characterized by unique peaks and troughs of methylation. Methylation patterns associated with maximum life spans generally differ from those connected to age or interventions that affect mortality risk in mice. These data provide a rich resource of information for fields including evolutionary biology and longevity research. —Di Jiang

DNA methylation networks underlying mammalian traits