A University of Wyoming researcher will receive a $1.17 million National Science Foundation (NSF) grant to study bumblebee cold tolerance across different elevations. The four-year grant begins Oct. 15.
To find out why some bees, for example, can tolerate cold above 8,000 feet elevation and others cannot, Michael Dillon, a UW associate professor in the Department of Zoology and Physiology, plans to study whether bees acclimate to local conditions and how cold tolerance is dictated by genetics.
“Bumblebees that are genetically similar may differ in cold tolerance,” says Dillon, principal investigator (PI) on the grant. “How can that be? There are many levels between the genetic code and the trait that could explain this.”
Franco Basile, a UW professor of chemistry, is co-PI on the UW grant. Vosnesensky bumblebees in Oregon and Washington will be the species studied under the NSF Emerging Frontiers grant, a part of the agency’s Understanding the Rules of Life program.
Dillon says the team discovered differences in cold tolerance in these bees while studying how widespread bee species adapt to diverse environments, supported by a previous NSF award. The new work also complements his ongoing work with the Insect Cryobiology and Ecophysiology (ICE) Network that received a $5.68 million NSF Established Program to Stimulate Competitive Research (EPSCoR) grant last year. Of that total, UW received a little more than $2.37 million over four years to study how bees overcome harsh winter conditions to successfully emerge and reproduce in the spring.
“The point of the new grant is to learn how you go from DNA to proteins to a trait like cold tolerance,” Dillon says.
Dillon describes DNA as the “blueprint for proteins in your body” and RNA is “essentially a draft drawing taken from the blueprint that is used to make proteins.” His focus will be on the physiology research, chilling the bees and measuring cold tolerance and its plasticity for bees from different populations.
A bumblebee experiencing a cold temperature may stop foraging, mating or pollinating flowers. A first sign is reduced activity. The bee may eventually stop grooming, cease walking and stop moving its antennae, Dillon says.
“Eventually, the bee gets to the point of ‘chill coma.’ It varies among bee populations, from as high as 1 degree Celsius to as low as 14 degrees below Celsius,” Dillon explains. “On mountaintops, bees have to tolerate extreme cold. Lowland bees don’t encounter such cold conditions. It’s like comparing living at the top of Medicine Bow to living in Fort Collins.”
Dillon says the research is practical because bumblebees and other bee species are in decline worldwide.
“We know climate plays a role. It’s not the only factor, but it’s a factor,” Dillon says. “Understanding their temperature tolerance will be really important in determining how they will adapt to changing temperatures.”
Additionally, he says if scientists can understand how these complicated traits, like cold tolerance, are controlled by the underlying genetics, that knowledge gained can be applied to humans and other animals.
“Hopefully, what we learn can be broadly applicable,” Dillon says.
The NSF grant UW received is in concert with a $1.4 million NSF grant received by the University of Alabama to study the same issue. Jeffrey Lozier, an associate professor of biological sciences at Alabama, is the PI and Janna Fierst, an assistant professor of biological sciences, serves as the co-PI.
Lozier says his team routinely analyzes different types of genetic and genomic data in his lab. His team will look at wild populations of bumblebees alongside those reared in laboratory colonies from different geographic regions to get at the genetic underpinnings of the bees’ adaptation to thermal extremes.
“We are particularly interested in determining if these differences are due to changes in DNA sequence between populations that have been shaped by long-term persistent evolution from temperature variation, or whether short-term temperature exposures to the individual or, in the previous generation, causes other kinds of modifications that alter physiology.”
To do so, Lozier says his group will sequence genomes and look at gene expression. In particular, he will look at reversible modification to the DNA itself.
With the work, he hopes to resolve some questions about how evolutionary adaptation of the bees is shaped by modifications to different levels of genetic variation and, in particular, to distinguish the roles of local adaptation from exposure to environmental extremes over long time scales versus individual plasticity shaped by recent environmental exposure.
“We expect that montane populations will be particularly sensitive to environmental shifts and we hope that, by understanding how populations ‘adapt’ to environmental gradients, that can help us make predictions about whether distributions can shift under global change, or whether we should be more concerned about population contractions over time,” Lozier says.
The grant also contains an outreach component. Dillon is working with UW’s Biodiversity Institute and the Shell 3-D Visualization Lab in the Energy Innovation Center to create a downloadable free mobile app for K-12 students. The app will include interactive visuals to explore the genetic underpinnings of complicated traits by going from “genome to phenome.” He expects the app to be functional by year two or three of the grant.