Deformed Wing Virus (DWV), one of the leading causes of honey bee colony losses, is much more genetically diverse in the United States than previously thought, according to a study published by Agricultural Research Service (ARS) scientists in PLoS Biology.
The diverse lineages of this virus are all equally bad for bees, and they make it more complicated to develop antiviral therapeutics, which could be the basis for developing a vaccine for the virus.
The high level of genetic diversity was found among the virus population within individual honey bees as well as within bee colonies. About nine percent of the nucleotides in DWV's RNA have polymorphic variants (places in the genetic sequence with natural alternatives) that are present at numbers higher than half of one percent of the virus population. This corresponds to 100 million to 1 billion virus copies for any single divergent genetic position in an infected individual bee.
"We found the genetic makeup of DWV in the United States is showing marked expansion in diversity after going through a strong bottleneck event, probably the arrival in the United States of the Varroa mite in the 1980s. Varroa seems to cause a dramatic loss of DWV genetic diversity in honey bees, because transmission by the mites favors a few more virulent strains," said virologist Eugene Ryabov, an International Fellow with the ARS Bee Research Laboratory, who led the study. ARS researchers Jay Evans and Judy Chen also worked on this study.
Read more at: US Department of Agriculture - Agricultural Research Services
Deformed Wing Virus, a leading cause of honey bee losses, has been found to be more genetically diverse than previously thought. (Photo Credit: ARS-USDA)