Unraveling Somatic Mutation Across Mammalian Species Shed Light on Aging with Dr. Cagan

In this episode, Dr. Cagan joins us to discuss his intriguing research on the rates and patterns of somatic mutation across a variety of mammalian species. Somatic mutation, the process of change in the DNA of an organism's cells other than sperm or egg cells, plays a key role in cancer and aging. However, the specifics of this process in non-human species have remained largely unknown.

Dr. Cagan and his team have shed light on the landscape of somatic mutation by conducting whole-genome sequencing of 208 intestinal crypts from 56 individuals across 16 mammalian species. They found that mutation is dominated by endogenous processes in all species, such as 5-methylcytosine deamination and oxidative damage. Interestingly, mutational signatures across species closely resemble those found in humans, though the contributions of each signature vary.

A key finding from Dr. Cagan's work is that the somatic mutation rate per year inversely correlates with species lifespan, suggesting an evolutionary constraint on somatic mutation rates. Despite the enormous variation in lifespan and body mass among the studied species, the somatic mutation burden at the end of lifespan only varied by a factor of around 3.

Join us as we delve into this fascinating research with Dr. Cagan, exploring the implications of these findings for our understanding of aging and evolution.

Keywords: Dr. Cagan, Somatic Mutation, Mammalian Species, Whole-Genome Sequencing, Aging, Cancer, Evolution, Lifespan.

https://doi.org/10.1038/s41586-022-04618-z Somatic mutation rates scale with lifespan across mammals