New research suggests that bats live exceptionally long lives and survive infections from some very nasty viruses because of genetic changes that probably evolved along with their ability to fly, Popular Science reports. Understanding those changes might eventually improve human health and longevity.
|Black flying fox (Pteropus alecto). © Merlin D. Tuttle
Scientists from the Australian Animal Health Laboratory and the Beijing Genome Institute studied the genes of two very different bat species: Australia’s large, fruit-eating black flying fox and the tiny, insectivorous David’s myotis of China. Their study was published in the journal Science.
The team determined that both bats were missing a gene segment that can cause extreme immune reactions to infection, Popular Science reporter Rebecca Boyle wrote. In most mammals, what actually kills is an inflammatory response called the “cytokine storm,” rather than the virus itself. And, she notes, this inflammatory response doesn’t happen in bats.
By understanding how bats suppress this response, researchers might be able to design new drugs to minimize inflammation in people, Chris Cowled, of the Australian Animal Health Laboratory, told the magazine. This, he said, could include anti-inflammatory drugs that take cues from bats to suppress the cytokine response, or a genetic therapy that targets certain segments of DNA.
But, Popular Science reports, “bats are not immune to everything. Millions of North American bats have perished from a fungal infection known as White-nose Syndrome.” The magazine notes that a different study recently concluded that hibernating bats are more susceptible to the fungus because their immune systems are suppressed. But when they awaken, their immune systems “go into overdrive. This is called immune reconstitution inflammatory syndrome, or IRIS. This has only been observed once before – in AIDS patients.”
Research into why bats handle many viral infections so well and fungal infections so poorly, and how bats’ immune systems differ from those of humans could, Boyle writes, “shed some light on human disease prevention.”
In addition to all this, Boyle notes, “bats have evolved to resist aging-related illnesses and cancer, the researchers say.” For mammals their size, bats are extremely long-lived, with typical life spans of 20 years or more. (The oldest confirmed bat lived at least 41 years, while field mice rarely live more than 4 years.)
The researchers told Popular Science that all this is likely due to bats’ ability to fly, an activity that burns vast amounts of energy – and “produces toxic free radicals that can cause tissue damage and cancer.” As a result, the two species in the study both evolved an abundance of DNA-repair genes.
“We’re proposing that the evolution of flight led to a sort of spillover effect, influencing not only the immune system, but also things like aging and cancer,” Cowled said.