In mammals, DNA methylation is an epigenetic mark that regulates gene expression by serving as a maintainable mark whose absence marks promoters and enhancers. Recent epidemiological studies demonstrate that DNA methylation levels are associated with aspects of biological aging in humans. We present universal mammalian epigenetic clocks that lend themselves for measuring age across mammalian species. We demonstrate that DNA methylation levels are strongly associated with maximum lifespan. These epigenetic clocks are expected to be useful for in vitro studies, animals models, and ultimately human clinical trials.
1. Define the concept of an epigenetic clock
2. Review evidence that epigenetic clocks are indicators of epigenetic age in mammals
3. Explain what is meant by universal mammalian clock