We leave DNA all over the place, including in the air, and for the first time, researchers have collected animal DNA from mere air samples.
The DNA that living things, human and otherwise, shed into the environment is called environmental DNA (eDNA). Collecting eDNA from water to learn about the species living there has become fairly common, but until now, no one had attempted to collect animal eDNA from the air.
“What we wanted to know was whether we could filter eDNA from the air to track the presence of terrestrial animals,” said study author Elizabeth Clare.
“We were interested in whether we could use this ‘airDNA’ as a way to assess what species were present in a burrow or a cave where we could not easily see or capture them,” she added.
As a proof-of-concept experiment, Clare and her colleagues tried collecting DNA from the air in an animal facility housing a model organism, the naked mole rat. The researchers detected both human and mole rat DNA in air from both the mole rat enclosures and the room where the enclosures are housed.
“The demonstration that the DNA from relatively large animals can also be detected in air samples dramatically expands the potential for airborne eDNA analysis,” said Matthew Barnes.
In the last decade, the collection and analysis of eDNA to study and manage plant and animal populations has taken off, Barnes said. “The analogy that I use is like the detective at the crime scene, finding a cigarette butt and swabbing it for DNA to place the criminal at the crime scene. We do that with eDNA except for instead of looking for criminals, we’re looking for a rare or elusive species,” Barnes said. The species might be endangered or an invasive species new to an environment, he said. Or humans of course…
Prior to this study, some researchers had collected plant DNA from the air, but most of those experiments involved plants that were “expected to intentionally release plumes of DNA into the air in the form of pollen and dispersing seeds,” Barnes said. Animals, on the other hand, don’t do that. “We had no idea if this would work,” Clare told Live Science.
But while animals don’t shoot pollen spores into the air, they do shed DNA in the forms of saliva and dead skin cells, for example.
The finding of human DNA within the animal enclosure at first surprised the researchers. However, given that humans care for the mole rats, it made sense in retrospect.
In the future, scientists hope to use the technique to monitor animal species in hard-to-reach dwellings.
It might also be a good way to detect species that are present but rare in a given environment, such as an endangered species. The method might give us an opportunity to survey for organisms without having to handle them and stress them out.
Now subscribe to this blog to get more amazing news curated just for you right in your inbox on a daily basis (here an example of our new newsletter).