Supplementary_file-mite-model.txt from Doomed drones? Using passage experiments and mathematical modelling to determine Deformed wing virus population dynamics in male honeybees

<i>Varroa destructor</i> is an ectoparasitic mite of honeybees which vectors a range of pathogenic viruses, the most notable being Deformed wing virus (DWV). Mites parasitise bees during pupal development and male honeybees, drones, have a longer development cycle than female workers (24 versus 21 days), allow for more progeny mites to develop per foundress (1.6–2.5 compared to 0.7–1.45). How this longer exposure time influences evolution of the transmitted virus population is unknown. Using uniquely tagged viruses recovered from cDNA we investigated the replication, competition and morbidity of DWV genotypes in drones. Assays examining virus replication and morbidity revealed drones are highly susceptible to both predominant genotypes of DWV. In virus passage studies using an equimolar inocula of major DNA genotypes and their recombinants, the recombinant form dominated but did not reach 100% of the virus population within 10 passages. Using an <i>in-silico</i> model of the virus–mite–bee system we examined bottlenecks during virus acquisition by the mite and subsequent injection of viruses into the host, which may play a significant role in shaping virus diversity. This study furthers our understanding of the variables influencing DWV diversity changes and provides insight into areas of future research in the mite–virus–bee system.

<i>狄斯瓦螨（Varroa destructor）</i>是蜜蜂的体外寄生螨，可作为媒介传播多种致病性病毒，其中最受关注的为变形翼病毒（Deformed wing virus, DWV）。螨类会在蜜蜂蛹期寄生宿主；雄蜂的发育周期长于工蜂（24天 vs 21天），因此每只定植雌螨可产生的子代螨数量更多（1.6~2.5 vs 0.7~1.45）。这种更长的暴露时长如何影响传播病毒种群的演化，目前尚不明确。本研究采用从互补脱氧核糖核酸（cDNA）中克隆获得的带独特标记的病毒，探究了DWV基因型在雄蜂体内的复制、竞争特性与致病效应。针对病毒复制与致病效应的检测实验显示，雄蜂对两种主要DWV基因型均具有高度易感性。在采用主要DNA基因型及其重组体的等摩尔接种物开展的病毒传代研究中，重组型病毒占据优势，但在10次传代内未达到病毒种群的100%占比。本研究通过构建<i>计算机模拟（in-silico）</i>的病毒-瓦螨-蜜蜂系统模型，分析了螨类获取病毒以及后续向宿主注入病毒过程中的瓶颈效应，该效应可能在塑造病毒多样性方面发挥重要作用。本研究加深了我们对影响DWV多样性变化的各类变量的理解，并为螨-病毒-蜜蜂系统的未来研究方向提供了新的视角。