Emergence and host switching in insect picorna-like viruses: wild and managed bee species as a model host community

蜜蜂是重要的家畜，因为它们具有授粉作用。近年来，特别是在中欧、北欧和北美，蜜蜂群体的损失不断增加。这些损失的一个主要原因被认为是病毒性疾病，特别是变形翼病毒（DWV）组的阳性单站RNA病毒。自从瓦螨进入欧洲和北美蜜蜂后，DWV的流行率上升，成为蜜蜂的一种新发传染病（EID）。与此同时，最近的证据表明，野生蜜蜂，包括大黄蜂和独居蜜蜂，已经感染了DWV和相关病毒，可能从蜜蜂那里蔓延开来；这些野生蜜蜂也是重要的传粉者。本项目采用实地取样、实地和半实地实验以及实验室分析相结合的方法，调查蜜蜂中DWV的出现是否伴随着病毒的遗传变化，病毒是否从蜜蜂向野生蜜蜂扩散，或反之亦然，以及新的病毒变体是否具有更高的毒力或传播能力。通过研究分布在多个宿主上的多种病毒，该项目将探索病毒出现和物种转换的早期阶段背后的机制，以及病毒出现对宿主群落的影响。

Honey bees are important domestic animals because of their pollination services. Recent years have witnessed rising honey bee colony losses, particularly in Central and Northern Europe and North America. A major cause for these losses is thought to be viral diseases, particularly positive single stand RNA viruses of the deformed wing virus (DWV) group. Since the arrival of varroa mites to European and North American honey bees, DWV has risen in prevalence to become an emerging infectious disease (EID) of the honey bee. At the same time, recent evidence demonstrates that wild bees, including bumble bees and solitary bees, have become infected with DWV and related viruses, potentially spilling over from honey bees; these wild bees are also important pollinators. This project uses a combination of field sampling, field and semi-field experiments and laboratory assays to investigate whether the emergence of DWV in honey bees has been accompanied by genetic change in the virus, whether virus is spilling over from honey bees to wild bees, or vice versa, and whether novel viral variants possess elevated virulence or transmission. By examining multiple viruses distributed across multiple hosts, the project will explore mechanisms behind the incipient stages of viral emergence and species switching as well as the consequences of viral emergence for the host community.