Airborne DNA could help scientists find elusive animals

A UK-based team said they were able to extract genetic material from the air and correctly identify the species to which it belonged, an exciting leap for the field of environmental DNA. The technique of sampling an environment for DNA to determine which organisms inhabit it, known as environmental DNA or eDNA, is routinely used to study terrestrial and marine environments – just see which molecular fragments can be found on forest floor or floating in the sea, and you will know which creature has passed recently. Now they’ve taken DNA straight from the air in an animal’s burrow.

Published today in the journal PeerJ, the research describes a lab setup in which they were able to detect airborne DNA. The test organisms were a group naked mole rats, settled in a makeshift burrow of pipes and tanks at Queen Mary’s University in London. The research team hammered a pipe into the animal tank and sucked in air, which fed a filter usually used for sampling marine electronic DNA. Next, the researchers performed genetic testing on the filter (which replaces animal tissue that would normally be tested for genetic material) and, to their surprise, were able to identify the rats only from the genetic material that floated in it. airspace of the burrow. .

“I tend to think of it a bit like soup,” lead author Elizabeth Clare, molecular ecologist at Queen Mary University in London, said on a video call. “We’re in the soup, and it’s got dust, pollen, and bits of DNA floating around … It’s one of those things where you even have to take a leap of faith to try it.”

The team weren’t sure if they would get anything out of the experience. While electronic DNA is common in land and maritime research, things move differently in the air. Molecular fragments need to be filtered out of the medium they float in to be read, and things quickly dissipate in the air if you are not in an enclosed space (hence the reason why the transmission of the coronavirus in outside is less likely than inside). This is why Clare’s team started with mole rats, a enigmatic species which weaves its way through networks of narrow underground tunnels. After successfully detecting mole rat DNA in the tunnel air, they expanded their testing to the lab itself. They were able to pick up human DNA in the air – theirs.

“The first question was quite risky: is there DNA in the air? The answer is yes, and we can capture it, ”Clare said. “The next question must become more risky: can we do it under more difficult circumstances?”

The implications for the detection of airborne DNA are significant. Clare works in the field with bats, whose habit of staying in dark, cavernous spaces or tiny chambers often prevents researchers from accessing bat colonies. EDNA in the air (called airDNA or maybe eDNAir – they’re working on it) would allow researchers to broaden their horizons of observation. Wherever it is used, the molecular detection method serves as a kind of biological call where species can make phone calls rather than needing to be directly observed.

Electronic DNA is a source of optimism for conservationists who are desperate to gain insight into endangered or elusive animals. This is useful for knowing all the characters in an ecological niche or understanding which animals have survived disasters like the Australian wildfires. Later – along the way – Clare is hoping that airborne DNA collection could help create a live map of biodiversity in a chosen area.