Wildlife Biologists Discuss the Role of DNA in Research
Short Talks From the Hill, a podcast from the University of Arkansas, highlights research and scholarly work across campus. Each segment features a university researcher discussing his or her work.
Bob Whitby: Hello and welcome to Short Talks From the Hill, a podcast from the University of Arkansas. I’m Bob Whitby, a science writer at the University of Arkansas. Today we’re talking to Michael and Marlis Douglas, both professors in the Department of Biological Sciences. Marlis holds the Bruker professorship in Life Sciences and Michael is the 21st Century Chair in Global Change Biology. Welcome.
Michael and Marlis: Thank you.
BW: You’ve been a lot of places, you’ve done a lot of interesting things. You’ve researched large fish in Bhutan; prairie chickens in Illinois; invasive Brown snakes in Guam; rattlesnakes in North America; desert fishes and deer in Arkansas, a lot of different animals. What do all of these studies have in common?
Michael: They all have in common DNA. We use DNA as our Rosetta stone to understand migrations of animals, to understand the genealogical relationships, how they relate to one another. We also figure out how much genetic variability is within a population so when you lose a lot of genetic variability that puts you in very dangerous straits for conservation and management.
Marlis: So, in other words, whatever happens to a species or a population over time.
BW: So this type of research is helpful to determine the health of a population?
Marlis: You can understand it as health but not necessarily how we would think of human health. A population in wildlife biology is considered healthy if it’s stable and if it’s large. In most cases for endangered species the population is declining, it gets smaller and smaller. The species might exist in only in small little fragments like the prairie chickens or the desert fishes. Invasive species are interesting because they usually start with little tiny populations at someplace where they introduced and then they expand and become very, very large populations. Humans today have a big influence on the environment. You know, we build roads we build houses where there maybe used to be prairie and so the animals and sometimes plants they can’t live anymore where they used to live. And so this has Impacts them, either the populations become very fragmented like in the case of greater prairie chicken, or the habitat simply isn’t there anymore.
Michael: Climate change is doing the same kinds of situations with these animals, it’s changing the queues for them to understand when to migrate and when not to migrate, and when to look for food and when not to food because all of that matrix is shifting on them.
BW: In the case of the prairie chicken, it was a conservation effort that, through the use of DNA you were able to show it’s not successful.
Marlis: Prairie chicken left in Illinois are in two distinct, different counties and there is no exchange between these two populations birds do not move from one side to the other and also they had introduced chickens from another place genetic signal that those chicken from Kansas for breeding successfully.
BW: Talk about a little bit about your work in Bhutan, an area of the world a lot of people aren’t familiar with. We’re sitting down in the recording studio right at the end of the spring semester and in a few days I think, or maybe a little longer, you’re going back over there to continue your work with this this very important, auspicious species of fish. So can you talk a little bit about what you’re doing over there and who you’re doing it for?
Marlis: So in Bhutan we work with the royal government of Bhutan and the fisheries biologists there the Department of Forestry and Conservation. Bhutan is a mountainous country, maybe people are more familiar with Nepal because there is Mount Everest and they know it’s very mountainous and searching the Himalayas.
Michael: Bhutan is just directly east of Nepal north of India, south of the Tibetan Plateau, so right in the Himalayas.
Marlis: And it’s a very small country – maybe the size of Switzerland. It calls itself also the Switzerland of Asia or Southeast Asia and so it’s maybe a quarter of this size of the state of Arkansas. And so it’s very mountainous it has all these beautiful streams and rivers which are from snow melt, and in these rivers live unique fish. And one of the fish we’re working which is the golden mahseer. What’s so fascinating, it’s a very large minnow. It’s a minnow which I think grew up to about nine feet it was very, very large. So in those larger rivers and those golden mahseer or one of the eight auspicious symbols of Buddhism. It’s Buddha’s eye, actually and in Bhutan it’s also the royal’s fish. So it’s a constitutional monarchy so they still have a king and only the king and his family are allowed to catch the golden mahseer. And of course we got permission for research to also catch golden mahseer. And it’s a very big fish and so what it does it kind of winters in the lowlands where the rivers are big and then kind of in the late summer when the monsoon starts it starts migrating up those streams.
Michael: You know it’s analogous to salmon in western North America where they’re spawned in these, up, up in mountain streams and they stay there for a short period of time and then they migrate down these streams out to the Pacific Ocean and then they grow out in the Pacific Ocean for a period of time and then when breeding time comes the ones that are able to breed, that are old enough to breed, will migrate back up these rivers again to their, right to their spawning sites, their natal sites. And they can hone in on these natal sites and of course building dams and that kind of thing now in Western North America has impeded the migration of these fishes and we’ve done great and expensive things to permit these fishes to get up to reproduce. There’s a push by India, of the country of India, to dam these Himalayan streams because you have gravity pulling that water down. All you got to do is put a dynamo in there and the water turns it you know, put a dam in a dynamo and you’ve got electricity. But then getting in there to build that dam and then getting out again and of course the environmental damage that is done are pretty serious things for the Bhutanese because they revere the environment and they revered this fish. They’ve converted 60% of their land in Bhutan to nature preserves so they’re really …
Marlis: Not just converted, it’s actually in their constitution that more than 60% of the land is dedicated to conservation.
Michael: So you can see they’re heading for a constitutional crisis in a way.
Marlis: It’s one of the least developed countries so hydropower has been recognized as one of these potentials. But we have known from what we’ve done in this country that hydropower can also cause a lot of environmental destruction because we change the rivers dramatically, we don’t allow fish to move anymore, and so there is great concern that if you build hydropower them in Bhutan that the fish won’t be able to migrate any more to their spawning grounds. And so our colleagues actually started that study with radio tracking where they put little transmitters in the fish and then they can track where they move so it’s similar like a GPS unit on your phone. And so they have some data which indicates that these fish indeed move up in these tributaries and spawn and so they got us involved to do the genetic study again. With genetic testing you can look how fish migrated over many, many generations, basically also leaves a pattern. So we kind of complement that radio tracking.
Michael: It’s important to say here that we don’t tell the Bhutanese, we don’t give them management decisions or anything, we give them data. We collect the data, we interpret the data, we provide them with the data, and then they make their management decisions based upon what they would like to do.
BW: One of your most recent research efforts has been to gather data on chronic wasting disease among deer in Arkansas. Can you talk a little bit about your efforts there and what you hope to achieve?
Marlis: Chronic wasting disease is a prion disease so it’s kind of a misfolded protein which causes, which is building up in the brain and causes brain damage and this is how they finally die. They waste away, they kind of get very skinny and start drooling and behaving weirdly and it’s very sad. It has been discovered in other states before, Colorado, Wisconsin, Illinois, but was detected I think in 2015 in Arkansas. It impacts primarily deer and elk and other cervids. And so what we do is not study disease itself, but what we study is how deer move across Arkansas, how they use the landscape to disperse from one area to the other. For example, female fawns they stay with the mother’s herd but the male fans they disperse. So they go someplace else and when we want to understand how this disease spreads from where it was originally discovered in Newton County to other counties we have to understand how the deer move. And our genetic studies kind of studied primarily how do deer move across the landscape and what might be barriers and what might be corridors. We would think a freeway is probably a barrier to a deer or a river can swim but probably doesn’t do it very often. So we do study one aspect which is very limited to the disease; that the gene which produces that protein which gets misfolded, it has different variants, different alleles; basically diversity, genetic diversity and it has been shown in other states that some of this diversity is associated with lower susceptibility of deer to contract the disease or if they have that allele or that variant then they’re less susceptible to chronic wasting disease.
Michael: The idea is to find out if there are pockets or clusters of this allele you know. Some areas have more individuals with resistance not an immunity and a resistance to CWD, and so if you can identify those and those areas then that’s promotional in a way because you can manage those better than others were where you have less opportunity to control the disease. DNA tells you where these deers move the DNA tells you how these populations are connected and the DNA tells you how related these populations are one to another and so you can decipher quite a bit about that disease by knowing the movement patterns of those deer.
Matt McGowan: Music for Short Talks From the Hill was written and performed by Ben Harris, guitar instructor at the University of Arkansas. For more information and additional podcasts go to kuaf.com or Researchfrontiers.uark.edu, the home of research news at the University of Arkansas.