Viruses can be found virtually everywhere, in every organism. This characteristic gives biologists the opportunity to use viruses as “biological airtags” to track and monitor their hosts without disturbing them.
It’s a hot summer day. Sweat is dripping from my forehead as I balance on wooden beams to collect my samples. It’s incredibly hot in here; I feel like I’m in a sauna! “Who on earth would crawl all the way up to the rafters of a church attic—in the middle of summer, no less?” I wonder as I try to grab a new pair of tweezers without losing my balance. That’s how I felt last summer during the fieldwork for my new research project.
I’m looking for bats—or, more specifically, their droppings. These droppings are teeming with microorganisms, such as bacteria and viruses, which can teach us a great deal about the behavior of our winged friends. I’m trying to figure out if I can use the viruses in those droppings as a kind of biological tracker to monitor the movements of bats.
A Transmitter That Goes Viral
It was quite a wild idea that popped into my head during a conference two years ago. The only thing I remember about it is that it had something to do with viruses and bioinformatics. But my thoughts had actually wandered off completely due to a “Eureka!” moment that I spent the rest of the conference turning into an idea I could present to my colleagues.
I was intrigued by the idea that viruses evolve incredibly quickly. Just think back to the rapid pace at which the different variants of the coronavirus followed one another—Alpha, Delta, Omicron. On top of that, there’s also the fact that viruses are completely dependent on their host (or their host cells) to survive and multiply. These two factors made me realize that we might be able to use viruses for nature conservation.
Biologists like me want to monitor plant and animal populations as closely as possible. That way, we can determine how well (or poorly) a particular species is faring. We’re also very interested in which populations are connected to one another, and how strong those connections are. The latter isn’t easy to determine, especially in animals, let alone bats.
Unfortunately, tagging doesn’t always provide an accurate picture of how closely two populations are connected, precisely because we can only gather information from a few individuals. We also don’t want to capture and tag every single bat. That would take far too much time and effort to carry out, and would disturb the bats too much.
Alternative methods are therefore more than welcome in this type of research. That is precisely why I want to investigate whether viruses might offer a solution here. As I mentioned above, viruses evolve at breakneck speed and are highly dependent on their host species. That is precisely why viruses seem so interesting to use as biological airtags—their evolutionary speed (the rate at which mutations and variants emerge) is nearly the same as the pace at which animals move and interact.
Needles in a haystack
That all sounds great, but it’s certainly not easy. You have to be able to find the viruses, of course, and to do that, you have to get close to their hosts. We want to disturb those hosts as little as possible. That’s exactly why we focus on collecting viruses from bat fecal samples. That way, we don’t have to catch the animals and we don’t cause them too much stress. We go inside, collect the freshest droppings, and we’re out again!
Now that we have the feces, the real challenge begins: isolating the viruses. That’s no easy task. You could compare it to looking for a needle in a haystack. Feces are full of other material, such as undigested food particles, gut bacteria, bacteriophages (viruses that infect bacteria), and even cells from the host itself. In fact, there are more things we don’t want in our samples than what we do want. Fortunately, there are various methods to solve this relatively quickly in the lab (within a few days), and we can separate the viruses from everything else.
Once we have our test tube of viruses, we can attempt to read their genetic code and determine how strongly viruses from different locations are linked to one another, and whether we can actually use them as airtags for monitoring their hosts.
Widely applicable
Currently, our focus is on two bat species: the Geoffroy’s bat (Myotis emarginatus) and the brown long-eared bat (Plecotus auritus). Bats are particularly interesting for this type of exploratory research because we know they can carry a relatively large number of viruses without becoming ill themselves. In the long term, we anticipate expanding our research to other animal groups, and perhaps even plants, because we know that viruses exist for virtually every type of organism roaming our planet. This would allow us to monitor species in an alternative way, with the ultimate goal of better protecting them.
This research is supported by the dedicated bat working groups of Natuurpunt and Natagora; without them, this would not be possible.
Are you interested in how this research will progress? Be sure to keep an eye on this blog! We hope to share our insights with you, and the rest of the world, in the future.
Original artikel can be found on the website of EOS Wetenschap