Researchers from Queen Mary University of London have shown for the first time that animal DNA shed within the environment can be collected from the air.
Environmental DNA (eDNA) is DNA that has been shed from various sources, such as saliva, urine or skin cells, of which can be accessed from the collection and filtration of non-biological substrates. Both intracellular and extracellular forms of eDNA can be released. This provides free strands of DNA, mitochondria and intact cells. eDNA is becoming increasingly important for biosurveillance, species occupancy studies and the detection of endangered and invasive species.
Researchers have found that abiotic and biotic factors are involved in shaping the release, persistence and degradation of eDNA. As a result, this shapes the timeframe for detection. For example, shedding rates have been found to increase under increased temperatures. The collection of eDNA from water is widely used and its application has expanded in the last decade. Nonetheless, other sources of eDNA, e.g., blood, soils, sediments, ice and snow, have received less attention. Despite growing interests, there has also surprisingly been no active attempts to collect animal eDNA from air.
In this study, published in PeerJ, researchers explored whether eDNA could be collected from air samples and used to identify animal species. This proof-of-concept study was conducted in a housing room which contained naked mole-rats. Naked mole-rats are a social rodent species that live in colonies. The researchers used existing techniques to check for DNA sequences within the sampled air.
Using this approach, the team were able to show that airDNA sampling could successfully detect mole-rat DNA within the animal’s housing as well as the room itself. They also found human DNA within the samples suggesting a potential use of this sampling technique within forensics.
The applications of this approach extend beyond ecological assessment into forensics, anthropology and also medicine.
Dr Elizabeth Clare, first author of the study, stated:
“For example, this technique could help us to better understand the transmission of airborne diseases such as COVID-19. At the moment social distancing guidelines are based on physics and estimates of how far away virus particles can move, but with this technique we could actually sample the air and collect real-world evidence to support such guidelines.”
Image credit: By LV4260 – canva.com