The key to living longer may be held by a common little bat residing in the US, the great brown bat, which boasts an unusually long life span of up to 19 years. A study led by researchers from the University of Maryland (USA) identifies one of the secrets of the exceptional longevity of this bat: the hibernation.
“Hibernation has allowed bats, and presumably other animals, to remain in northern or very southern regions where there is no food in winter,” explains study lead author Gerald Wilkinson. “Hibernators tend to live much longer than migrants. We knew that, but we didn’t know if we would detect changes in epigenetic age due to hibernation.”
The scientists determined that winter hibernation prolongs the bat’s epigenetic clock – a biological marker of aging – by three-quarters of a year.
In the study, published in the journal “Proceedings of the Royal Society Bon”, in which scientists from McMaster University and the University of Waterloo, both in Ontario (Canada), also participated, small tissue samples taken from the wings were analyzed. of 20 great brown bats (Eptesicus fuscus) during two periods: in winter, when they hibernated, and in summer, when they were active. The bats, kept at a McMaster University research colony, ranged in age from less than a year to just over 10.
Once the samples were collected, changes in DNA methylation – a biological process associated with gene regulation – were measured between samples taken from the same animal during periods of activity and hibernation. They found that changes in DNA methylation occurred at certain locations in the bat genome, and that these locations seemed to affect metabolism during hibernation.
“It’s pretty clear that the sites that decrease methylation in winter are the ones that seem to have an active effect,” says Wilkinson. Many of the genes that are closest to them are known to be involved in regulating metabolism, so presumably they keep metabolism down.”
Hibernation prolongs the bat’s epigenetic clock by three-quarters of a year
Some of these genes are the same ones that Wilkinson and other researchers identified as “longevity genes” in an earlier study.
Wilkinson points out that there is significant overlap between hibernation and longevity genes, highlighting the relationship between hibernation and life extension.
The earlier study also established the first epigenetic clock for bats, capable of accurately predicting the age of any bat in the wild. That clock was applied to this latest study, allowing the researchers to show that hibernation reduces a bat’s epigenetic age compared to a non-hibernating animal of the same age.
Studies like this one help explain why bats live longer than expected for a small mouse-sized mammal. However, they also raise new questions.
«We still don’t really know why some bats can live a long time and others don’t.Wilkinson says. “We have shown that long-lived ones share the ability to hibernate, or go into torpor frequently. That seems to be a corollary, but it’s not enough because other hibernating rodents don’t live 20 years.”
Wilkinson said he is planning a follow-up study to compare epigenetic aging in great brown bats in Canada, where they hibernate, with the same species in Florida, where they don’t hibernate. With this, Wilkinson hopes to get an even clearer picture of the role that hibernation plays in prolonging life.