Q&A with PhD student Christian Gagnon
Christian Gagnon is a PhD candidate studying Biological Anthropology and working in the SMAGL lab with Dr. Chris Schmitt and Dr. Eva Garrett. Prior to joining the BU Anthropology Department, Christian received his BA and MA in Anthropology from CUNY Hunter College. His research broadly focuses on better understanding the evolution of complex traits.
Q: Congratulations on winning 2nd place in the NEEP Best Poster Presentation! Can you tell us about your current research project?
A: My research right now focuses on the molecular evolution genes associated with non-shivering thermogenesis in brown adipose tissue. Over evolutionary time, many mammalian lineages have experienced selective pressures to be able to withstand thermos-regulatory stress due to low temperatures. Because mammals are warm-blooded. we have to maintain a core body temperature between a certain range in order for our physiology to function the way it is supposed to. We suggest that there are certain traits that would make that more efficient. For humans and primates more generally, we started in an equatorial environment and then expanded out to colder climates across the world. Even though this is mammalian trait it holds a particular significance for our species, as a species that is very adaptable and flexible and is known to inhabit some of the coldest places on earth. There’s selection that occurred across the mammalian lineage, but we also expect to see this selection at the population level. This was the seed of everything I’ve done so far. I use savanna/vervet monkeys as a model for the evolution of early hominids. They share a relatively close phylogenetic relationship in common with humans, and they started in an equatorial place and expanded into the southern most regions of Africa where temperatures can be quite cold, even freezing in some areas, which is unusual for non-human primates. I am investigating if there was in fact selective pressures that resulted in meaningful functional variation across populations facing different thermoregulatory challenges. I have been very fortunate to have access to the considerable resource of the vervet research consortium. Using whole genome data, we have looked at population variation in the following gene regions: UCP1 gene, the FAB4 gene, and PPAR gamma.
I’m looking for signals of selection — looking at population level differences in vervets and what selective forces have acted on those gene regions to test the hypothesis that there’s a benefit to having variants of these genes which promote non-shivering thermogenesis efficiency.
I also look at the phylogenetic history of these genes across all primates, and from that, I can tell old world monkeys have this very specific version of this gene vs. strepsirrhines who have a different version. Then I look at key interaction sites in those genes to see how different they are across different species and if there are any patterns there.
Now, I am furthering this work by trying to validate those signals of selection at the population level to determine if they account for functional differences in non-shivering thermogenesis. I’m validating this functionality using cell culture methods. I use fibroblasts from savanna monkeys and chemically convert them into the cells that I want (brown fat cells) by exposure to specific chemicals. Brown fat is a really difficult tissue to obtain by any other means. I can then do invitro experiments in a lab on these cells to see if the different gene variants I am investigation have an effect on gene expression. To sum it up, I study the evolution of genes associated with brown adipose mediated non-shivering thermogenesis, the genetic variation that exists across species & populations, and how these e variants relate to functional variation.
Q: How did you get involved with that?
A: I started out in a molecular lab at Hunter College, so that’s how I got my foot in the door with genetics/bioinformatics. I came to Boston University to work with Chris Schmitt because bioinformatics is one of his strong suits. I didn’t see the cell line stuff coming; if you asked me when I first got here, I didn’t think I’d be into cell line. I kind of fell into it by chance. Once I started working with the brown fat tissues, I stumbled onto cell culture through a colleague that I met who used to be a PhD student in the lab I work in at UMass Amherst; she told me about the work she was doing with the precursor cells of non-human primates and I wondered if I could do the same thing with brown fat. I did some background research and found that someone had tried to do that and developed a protocol for it using human stem cells. At that point, I realized it was a possibility – we had the fibroblasts, I had access to Chris’s data through his vervet research program, and then it all came together. Then it was a matter of where I was going to do the cell line work, since it requires a lot of specialized equipment. I reached out to collaborators and landed on the Babbitt lab at UMass. There aren’t a lot of anthropologists doing cell line work; it is cutting edge in biology where they have the funding to do this stuff, but in anthropology it is much harder to come by. I can think of maybe 4 other anthropologists who do this. It’s exciting; I hope that this becomes a more mainstream approach and I hope that I can play a part in exposing other students and researchers to this. Once this part of my project is done, I’ll be really proud of it. I like trying new things and approaches and being on the cutting edge, approaching questions that anthropologists haven’t really considered before. And technology has gotten so amazing that we can start doing this stuff.
Q: What made you decide to be a biological anthropologist?
A: When I was in undergrad I was premed student aiming to go to medical school. Senior year, I took a class in bioanth with Mike Steiper. I didn’t know what anthropology was and I took it as an elective to fill a requirement, but as soon as he started talking about evolution and primates, I thought it was the most interesting class I’ve taken in my life. I still didn’t fully understand what anthropology meant, but my professor saw the passion I had for it – I was always asking questions, engaged and motivated in the lab exercises, picking up on things some of the other students who didn’t care as much weren’t picking up on. He told me he thought this was a field I’d excel in and offer me a fellowship in his lab – that’s where it all started. After that, things just kept reinforcing that this is where I’m meant to be. Per his suggestion, I did a field course in Uganda, which was my first experience in primatology. It was so amazing and formative, and I never looked back. This is what I want to do. I want to be a primatologist. I want to be in academia. I’ve waned on it once or twice since it is not an easy road to take, but I’m still super passionate about primatology, bioanth, evolution. I still find them more interesting than any other topic. For me, it’s the ultimate puzzle, the ultimate mystery. We can’t fully it but we can work toward a better understanding of it. And if I can contribute to it, that’s where I want to be.
Q: Any exciting ideas for possible future research projects?
A: There’s still so much work to do on brown fat. It’s a really poorly understood tissue type, and it has so many implications for other things – obesity, maintenance of weight, energy consumption, fat storage, etc. In the long term, I’d like to have a field program where I work with wild primates, maybe I’ll stick with vervets or maybe I’ll go with a different species like Japanese macaques, but I feel like there’s still a lot to do with the brown fat. My broader goal is still to study the evolution of complex traits – anything to do with diet, energy storage, thermoregulation. I’ll probably focus on those for the vast majority of my career if I’m lucky.
Q: What has been the most enjoyable part for you so far?
A: I’ve gotten to the point where I am now by a pretty unconventional path — to be 39 years old and getting a PhD, having had kids and a career before coming into this whole thing. I was a fireman before going back to school. But I think that speaks to following your passion. If you can figure out a way to do what you’re passionate about and make ends meet, that was more important to me than going the medical school route and getting the guaranteed job and income. I don’t regret that at all because I see the value in what I do and I think that bioanthro in particular has given me a very interesting perspective on how I approach things in my every day life and in my research. That perspective is really valuable and I wish more people were exposed to bioanthropology.