Why bats?
A mammals lifespan tends to be linked to its body size. So in theory, the larger the species, the longer it will live. Bats seem to be an exception to this rule with an unusually long lifespan for their body size. Some are shown to live more than four times longer than similar sized mammals.
The big brown bat (Eptesicus fuscus) is the most common bat in North America. A 2022 study on a colony of bats in Ontario, Canada has been looking into their unusually long lifespan of up to 19 years and found a link between longevity, biological ageing and hibernation!
A previous study had contributed to the discovery of “longevity” genes. The more recent research suggests that these genes are very closely associated to those related to hibernation.
How do they know?
A biological process involved in the way in which genes are expressed, called DNA methylation, was measured to find that changes in this process took place in certain parts of the bat genome related to metabolism. During hibernation, the genes affected had decreased DNA methylation activity at these sites suggesting that they were keeping body metabolism down. These are the genes that overlap with the “longevity” genes forming the suggestion for a link between longevity and hibernation.
Ageing
The previous study looked for a biological marker of ageing which can be used to measure the age of a bat. A biological marker or biomarker, is a characteristic that is measured and evaluated as an indicator of normal biological processes. In this case, the biomarker is called an epigenetic clock. The 2022 study has found that one winter hibernation can increase a bat’s epigenetic clock by three quarters of a year. This means that a hibernating animal would have a lower epigenetic age compared to a non-hibernating animal that is the same age. Therefore, suggesting that the ageing process is slowed during hibernation.
What’s next?
Researchers are now planning follow a follow up study to further investigate hibernation and lifespan. They hope to compare the research of the bats in Canada with a same species group found in Florida which do not have the same need to hibernate.
Bats are a favourite here at chXout so we will be looking forward to seeing how the research will progress!