How Tiny Bats Can Help Us Extend Human Life
That's right. Bats.
They might seem small and delicate, but they are actually pretty tough. They live long lives for their size, and seem to withstand the diseases and other effects of aging that bring other animals down. Because of that, scientists have been studying them for clues to their hardiness by analyzing their genomes.
Last year, a group led by "Bat Man" Lin-Fa Wang, of Duke-NUS Graduate Medical School in Singapore, sequenced the entire genome of two distantly-related bat species: the flying black fox and David's Myotis.
An analysis of these genomes found one key to bats' tough immune systems: their ability to fly.
Flying and health
Flying is an energy-expensive activity, and it releases a lot of toxins into the body from processes in the muscles - which is also why our muscles ache after a work out. As the only flying mammals, bats have evolved the unique ability to resist these toxins, along with many of the others that would cripple another animal.
"The most outstanding difference we've seen between bats and other mammals has to do with DNA repair," Wang told Bloomberg. "If the science is as true as we think it is, we can unlock the mechanisms and it can have a huge, huge impact."
There are probably multiple ways that the bats extend their lifespan. Another group of scientists, from Harvard University, analyzed the genome of the tiny Brandt's bat and found another explanation for their disease-resistance - their small size.
A tiny bat with a long life
Typically, a larger size correlates with a longer lifespan in animals (for example elephants, who can live up to 70 years). Smaller mammals like mice usually only live about 18 months. But bats, many of which are quite small, turn this correlation on its head.
The tiny Brandt's bat, which Gladyshev's team studied, is the size of a mouse and can fit in the palm of your hand. But it lives for about 40 years. This "longevity quotient" - the ratio of its size to lifespan - is more than double that of humans, already an incredibly long-lived species.
Apart from certain life-extending behaviors like cave-roosting, hibernation, and having few offspring, it turns out the Brandt's bat has a mutated growth hormone receptor lining on the outside of its cells. This mutation keeps its body small, while contributing to its long life, just as it does for dwarf mice, and even some humans.
The results were reported in the journal Nature Communications on August 20, 2013.