D
agan Loisel, a geneticist by training, is passionate about his work.
“My prediction is that we will see a great deal of genetic variation,” says Loisel. “And genetic variations indicate changes in the coding sequences of proteins. Genes fight viruses. So a species with many genetic variations may be more After doing his able to fight disease.” Researchers target graduate work on the DNA of the pathogens — they baboons in Africa, Loisel turned to humans, take liver and spleen samples and extract with post-doctorate work on asthma. “I the DNA of the virus. They also look wanted to continue to study mammals,” he for antibodies in the blood. says, surrounded by photos of wild cats and baboons. When he came to Vermont, The technology used to study gene Loisel got samples from bobcat carcasses sequencing is changing rapidly. “We’ve collected from hunting, trapping, and gone,” says Loisel, “from taking 20 years roadkill by the Vermont Fish & Wildlife to sequence a genome to one month
Populations with a high rate of genetic diversity (like baboons) have a greater chance of developing mutations to resist disease. Has natural selection played a role in genetic diversity? Can we connect that evolution to disease resistance and health? Loisel envisions enormous possibilities in other realms like social justice. Every virus in wildlife has the potential to become a human virus. We are big, but vulnerable, mammals. We have vaccines, he explains, but the number one cause of immune deficiency
Beauty of Diversity An Interview with Dagan Loisel by Susan Salter Reynolds
Department. “I’m not a big fan of destructive sampling,” he says with a shy grin. He began keeping track of the health of various populations. The lab freezer on the 3rd floor of Saint Michael’s Cheray Science Hall contains 300 muscle samples from across the state — cats of different ages, sizes, and regions. Using these samples, students make a map of their genetic variation. “Within any population there are variations affecting, among other things, the immune system,” he explains. How much genetic diversity is there in bobcats in Vermont? Is there a genetic variation that is important for fighting disease? “Felines provide a great model for studying viral pathogens in humans. What is the first line of defense in felines against pathogens?” he asks. Bobcats, apparently, will eat anything, so these samples contain pathogens from mice, rabbits, squirrels, and many other delicacies.
and $1,500.” Humans are easy — their genome has been sequenced. But bobcats don’t have that scaffolding. Loisel recently received a grant to study pathogens and parasites in wild cats at Colorado State University, where he will learn new genetic sequencing techniques that will allow researchers at Saint Michael’s to get definitive answers. Loisel loves putting undergraduates to work. “Many students are interested in healthcare — they are trying to decide whether to become practitioners or do biomedical research. By conducting research on the complex immune system, students get a good idea of which path they want to choose.” Genetic variability, he hypothesizes, is important for disease resistance. In other words, diversity will keep us alive. If 5 percent of a population has a resistance allele, there’s hope against a pathogen.
is malnutrition. Poverty, malnutrition, and compromised immune systems are often seen together. What if we could put disease-resistant alleles in people with certain viral disorders? How can we keep ourselves safe? These are the questions that keep Loisel deeply engaged in his work.
15