Advisor(s)
Abstract(s)
The main biological threat to the western honeybee (Apis mellifera) is the parasitic mite Varroa
destructor, largely because it vectors lethal epidemics of honeybee viruses that, in the absence
of this mite, are relatively innocuous. The severe pathology is a direct consequence of excessive
virus titres caused by this novel transmission route. However, little is known about how the virus
adapts genetically during transmission and whether this influences the pathology. Here, we show
that upon injection into honeybee pupae, the deformed wing virus type-A (DWV-A) quasispecies
undergoes a rapid, extensive expansion of its sequence space, followed by strong negative selection
towards a uniform, common shape by the time the pupae have completed their development,
with no difference between symptomatic and asymptomatic adults in either DWV titre or genetic
composition. This suggests that the physiological and molecular environment during pupal
development has a strong, conservative influence on shaping the DWV-A quasispecies in emerging
adults. There was furthermore no evidence of any progressive adaptation of the DWV-A quasispecies
to serial intra-abdominal injection, simulating mite transmission, despite the generation of ample
variation immediately following each transmission, suggesting that the virus either had already
adapted to transmission by injection, or was unaffected by it.
Description
Keywords
Citation
Yañez, Orlando; Chávez-Galarza, Julio; Tellgren-Roth, Christian; Pinto, M. Alice; Neumann, Peter; de Miranda, Joachim R. (2020). The honeybee (Apis mellifera) developmental state shapes the genetic composition of the deformed wing virus-A quasispecies during serial transmission. Scientific Reports. ISSN 2045-2322. 10:1, p. 1-12