We leave DNA everywhere, including in the air, and for the first time, researchers have collected animal DNA from mere air samples, according to a new study.
The DNA that living things, human and otherwise, are dumped into the environment is called environmental DNA (eDNA). The collection of eDNA from water to learn about the species that live there has become quite common, but until now no one has tried to collect animal eDNA from the air.
“What we wanted to know was whether we could filter eDNA from the air to detect the presence of terrestrial animals,” said author Elizabeth Clare, an ecologist at Queen Mary University of London. video abstract for the study, published March 31 in the journal PeerJ. “We were interested in whether we could use this ‘airDNA’ as a way to determine which species occur in a cave or a cave, where we could not easily see or capture it,” she added.
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As evidence of conceptual experimentation, Clare and her colleagues attempted to collect DNA from the air in an animal facility in which a model organism, the bald mole. The researchers detected both human and mole rat DNA in the air from both the mole rat boxes and the room where the boxes are located.
“The demonstration that the DNA of relatively large animals can also be detected in air samples dramatically increases the potential for eDNA analysis in the air,” said Matthew Barnes, an ecologist at Texas Tech University in Lubbock. new study was not involved, said.
In the past decade, the collection and analysis of eDNA for the study and management of plant and animal populations has increased, Barnes said. “The analogy I use is like the detective at the crime scene, finding a cigarette butt and swiping it for DNA to put the criminal on the crime scene. We do it with eDNA, except we’re looking for criminals, but we are looking for a rare or elusive species, “Barnes said.” The species could be endangered or an invasive species that is new to an environment, “he said.
Prior to this study, some researchers collected plant DNA from the air, but most of the experiments involved plants that “were expected to intentionally release DNA plumes into the air in the form of pollen and seed dispersal,” said Barnes. Animals, on the other hand, do not. “We had no idea if it would work,” Clare told WordsSideKick.
But although animals do not shoot pollen spores into the air, they shed DNA in saliva and dead skin cells, for example. To see if animal eDNA could be collected from these sources, Clare and her colleagues vacuumed air from a shell of naked mole rats and from the room that houses the housings through filters similar to the HEPA filters commonly used in heating and ventilation systems occur. The researchers then extracted DNA from the filters and placed it in order. To identify the species from which the DNA came, the researchers compared the sequences with reference sequences in a database.
The discovery of human DNA in the shell of animals at first surprised the researchers, Clare told WordsSideKick. Since humans care for the mole rats, it made retroactive sense, Clare said.
The presence of human DNA in almost every sample from the study is a major obstacle, ‘Barnes said. On the one hand, it shows encouragingly that the detection method is sensitive, Barnes said. But “it could also suggest that samples from the air could be particularly easily contaminated with DNA from the research team, especially if mammals are the target for analysis,” he added.
To avoid such pollution, researchers may need to use clean room techniques – think of air filters, gowns and hair nets – to prevent their DNA from being added to the environments they study, or DNA samples they work with.
In the future, scientists hope to use the technique to monitor animal species in hard-to-reach homes. “I would suggest sticking a tube in a box or in a tunnel system and sucking the air out of the system rather than trying to locate the animals to find out what’s present,” Clare told WordsSideKick .
It can also be a great way to spot species that do occur, but are rare in a given environment, such as a endangered species, she added. And it can help detect a species without communicating with it, which could have benefits, Barnes said. “[The method might] ‘gives us the opportunity to investigate organisms without dealing with and emphasizing them,’ he said.
The question of whether eDNA analysis enables scientists to estimate population sizes, or the number of animals living in a dwelling, but Clare said she does not think well of it. “There are too many steps in the procedure that can cause the amount of DNA you collect to vary,” she said.
Now Clare and colleagues are studying how far airDNA can travel and how the size of the space affects how much eDNA can be detected, Clare said in the video summary.
Another important step in studying airDNA from animals is to try to collect airDNA from animals outside, rather than in a research laboratory, Barnes said.
Originally published on Live Science.