|RYABOV, EVGUENI - Non ARS Employee|
|POSADA, FRANCISCO - Non ARS Employee|
|WEAVER, DANIEL - Bee Weaver, Llc|
|VANENGELSDORP, DENNIS - University Of Maryland|
|Chen, Yanping - Judy|
Submitted to: PLoS Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2019
Publication Date: 10/10/2019
Citation: Ryabov, E., Childers, A.K., Lopez, D.L., Grubbs, K.F., Posada, F., Weaver, D., Vanengelsdorp, D., Chen, Y., Evans, J.D. 2019. Dynamic evolution in the key honey bee pathogen Deformed Wing Virus. PLoS Biology. https://doi.org/10.1371/journal.pbio.3000502.
Interpretive Summary: Honey bees provide critical pollination services worldwide and a cash crop for farmers. Managing honey bee colonies against disease remains costly and beekeepers routinely lose half of their colonies annually. A main cause of bee losses is the varroa mite and viruses transmitted by this mite. Here, for the first time, we use cloned viruses to explore virulence and competition among variants of Deformed Wing Virus, an important honey bee virus. We show that strains do not exclude each other and if anything it appears that diversity of viruses is maintained because rare types are better able to avoid honey bee immune responses. The results have strong implications for gene-based control of viruses and the regulation of borders against new strains.
Technical Abstract: Deformed Wing Virus (DWV) is implicated in honey bee losses worldwide. DWV virulence is magnified when vectored by the parasitic mite Varroa destructor with specific DWV phylotypes being favored by selection. To test the evolutionary dynamics of DWV infections, we designed a series of infectious cDNA clones corresponding to co-existing genetic variants. All tested variants replicated equally well compared to diverse natural DWV populations without strong competitive exclusion. Recombination events observed across progeny of the clone-derived DWV genotypes contribute to virus diversification. We propose a new model of Varroa-induced DWV dynamics whereby Varroa-adapted genotypes fixed by drift and initial selective sweeps then undergo diversification resulting in high genetic heterogeneity, potentially benefiting the virus given a negative frequency-dependent selection for new genotypes.