Irish scientists have discovered a key reason why certain species of bats have extraordinarily long lifespans relative to their tiny body size.

Their findings could in time help with the development of ways to slow down the ageing process in humans and extend our healthy period of life by explaining what is one of the least well-understood processes in biology. 

The study, led by researchers in University College Dublin, focused on the longest-lived species of bats which have a very long life span, despite being a small mammal. 

In particular they focused on telomeres, which are the protective structures of DNA at the end of chromosomes that shorten with age in humans and in other animals. 

This causes cells to breakdown as the person or animal gets older, leading to the deterioration of tissue and eventually to death.

The UCD scientists wondered whether the reason why bats live unusually long lives could be related to their telomeres. 

Irish researchers working with colleagues across Europe captured 500 wild bats across four species and took 3mm wing biopsies and blood samples from them before marking and releasing them.

They then carried out an analysis of the telomeres and to their surprise found they remained long in certain species of bat throughout their lives.

"Our results show that telomeres shorten with age in two of the bat species, typical of most mammals," said Dr Nicole Foley, from the Batlab at UCD and lead author of the resulting paper published today in Science Advances. 

"But in the longest-lived species of bats, Myotis, we did not detect any evidence that their telomeres shorten with age, contrary to all expectations." 

While other species use an enzyme called telomerase to trigger the repair or reversal of telomere damage, none was found in the bats. 

Instead, the researchers suspected that bats have developed a way of lengthening their telomeres without triggering the common result, cancer. 

So they dug deeper, examining the genetic code underpinning the telomere maintenance by comparing the bat genomes to those of 52 other mammals. 

Within the 225 genes known to be associated with telomeres, the team found two genes ATM and SETX responsible for the resilience. 

"Our results suggest that long-lived bats have evolved better mechanisms to prevent and repair age induced cellular damage," said Professor Emma Teeling, a senior author on the paper. 

The team, which involved researchers from ten different institutes across five countries, says the results coupled with further research may present exciting ways of slowing down ageing and ultimately extending the healthy period of life in humans.