The honey bee population has suffered unsustainable losses since 2006, though the reason why is not fully understood. In a Café Scientifique presentation on March 27, Michelle Flenniken, Ph.D., a virologist investigating the impact of viruses on honey bee health in MSU’s Plant Sciences Department, shared her research on the subject.
One-third of the foods we eat as Americans would not be available to us without pollination by honey bees, therefore, Flenniken pointed out, the question of what’s killing them is a pertinent one.
There is no one cause, Flenniken told a crowd containing many local beekeepers, but multiple factors contribute to the decline, including habitat loss, agrochemical exposure, inadequate floral resources and pathogens.
“In bee colonies that were affected by colony collapse disorder,” Flenniken said, “there was a greater abundance of pathogens than healthy colonies,” which was part of what drew her into studying bees in her post-doctoral research in microbiology and immunology at UCSF.
Flenniken’s research has focused on immune responses in the honey bee population, such as RNA-interference to combat pathogens. The largest group of honey bee infecting pathogens are viruses that have an RNA genome.
Eukaryotic organisms like humans and honey bees have a DNA genome (or genetic blueprint), which is transcribed into RNA (an intermediary messenger molecule), which is then translated into proteins that carry out most of the important biological functions.
“RNA-interference does just what its name suggests,” she told the audience. “It interferes with RNA. And if you don’t get any RNA, you have no protein and, in turn, no virus.”
Laura Brutscher, a doctoral student working in the lab with Flenniken, has been injecting honey bees with double-stranded RNA, a molecule produced when viruses replicate. It serves as an immune-stimulating molecule — meaning that it triggers the bee’s immune system to fight off virus infection.
“What [Brutscher] has found is that double-stranded RNA treatment reduces the amount of virus in the bees. And that’s a pretty important result,” Flenniken said.
This research has allowed the team to better understand which genes are involved in combatting viral effects in honey bees.
“It may be that these [genes] become targets for selective breeding programs of our bees to better defend themselves against viruses,” Flenniken said.
It’s possible that the research leads to colonies that are naturally more able to withstand viral infection.