But for many biologists, keeping track of mammals that move miles every day and are wary of humans may be nearly impossible. Enter eDNA. “If we are to restore ecosystems, we need to understand how our conservation actions affect threatened and endangered species. But to do that, we need to be able to spot even the rarest, shyest, and most mysterious species,” wrote Michael Schwartz, chief scientist at the Center for Disease Control and Prevention. The National Genomics of Wildlife and Fish Conservation of the US Forest Service in Missoula, Montana, in a wired email. “We need new technologies, such as the ability to detect airborne environmental DNA.”
Schwartz, who was not involved in the two new studies, uses samples of air, water and soil to track large brown bats (Eptesicus fuscus), whose numbers have been devastated by white-nose syndrome, a fungal-borne disease that arrived in the United States in 2006. Schwartz and colleagues published a study in September in the journal biological conservation which examined eDNA samples from soil and water outside the caves where bats roost. They also used an air sampler as part of the project to see if they could capture airborne DNA from a bat enclosure in Ohio. The study revealed that six of the seven filtered air samples successfully detected RNA in the air, but concentrations were low, despite the presence of 30 bats in the room.
Schwartz says his colleagues are refining their air sampling techniques and working on a method for collecting small amounts of DNA from snow. This not only allows the USFS team to discover which mammal species have traveled recently On Snow block, but pits to me It also allows them to find evidence that a certain type of animal traveled through the area months ago. Schwartz’s group has published some of the findings on this project in the journal biological conservation in 2019. Using ice tracks to spot timid predators like lynx is cost-effective, efficient, and ultimate, he says.
Will air-to-air DNA sampling succeed in tracing genetic material from individuals? Hypothetically yes, but in practice no, says one expert. “This is possible, but it would be a little more difficult,” says Melania Cristescu, associate professor of environmental genomics at McGill University, who uses eDNA to sample aquatic habitats. It is easier to analyze parts of human DNA from hair, saliva, blood or any other genetic material left on surfaces than it is in the air. (Swiss researchers recently solved a family-origin mystery using DNA from postage stamps stuck to a postcard from World War I, which shows the molecule’s stability under certain conditions.) But it would take a longer enough sample of airborne genetic material. , and researchers will have to be very careful not to allow their DNA to contaminate the filter.
With airborne DNA, weather is also a factor. Sampling may not work well if it is rainy or windy, for example, because these conditions may clear the air of particles that carry DNA. Nor is it clear how well the molecule tolerates heat or bright sunlight. “Does solar radiation degrade DNA? Probably, but we don’t know at what rate,” Claire says. We don’t know how far wind can scatter DNA. We do not know how temperature might affect their rates of degradation. These are all really interesting questions.”