The Role of Host-Pathogen Coevolution in the Population Dynamics of an Insect-Virus Interaction

最新的理解宿主-病原体相互作用的方法假定宿主-病原体种群动态和宿主-病原体共同进化是两个独立的主题。此外，寄主-病原菌的共同进化通常被认为是关于病原菌的毒力，而不是关于寄主抗性或真正的共同进化。然而，在以往关于舞毒蛾与病毒相互作用的研究中，PI收集的数据表明，寄主对病毒的抗性变异性在舞毒蛾暴发中起着重要作用，对该系统进行模拟的初步尝试表明，抗药性的进化可能推动了舞毒蛾的暴发。因此，抗性的进化和种群密度的波动似乎是理解吉普赛蛾与其病毒之间相互作用的关键，而病原菌毒力的进化可能在很大程度上是重要的，因为它有助于保持寄主抗性的多样性。本研究将调查以下问题：寄主抗性是否会导致吉普赛飞蛾的种群暴发？寄主抗性的可变性是如何维持的？回答这些问题的方法将是记录几个暴发的吉普赛蛾种群在这些种群因病毒流行而崩溃期间寄主抵抗力和病原体毒力的变化。此外，我们还将量化吉普赛飞蛾对病毒抗性的可加性遗传变异，以了解这种昆虫进化变化的可能性。此外，我们还将探索宿主-病原体特异性和/或宿主和病原体之间的适合性权衡是否有助于维持宿主抗性。这将有助于将种群动力学和进化动力学这两个以前截然不同的领域结合起来，并可能有助于阐明管理这种害虫的策略。

0075461DwyerMost recent approaches to understanding host-pathogen interactions assume that host-pathogen population dynamics and host-pathogen co-evolution are separate subjects. Moreover, host-pathogen co-evolution is often assumed to be about pathogen virulence, rather than about host resistance or true co-evolution. In previous research on the interaction between gypsy moth and its virus, however, the PI has collected data showing that host variability in resistance to the virus plays an important role in gypsy moth outbreaks, and the preliminary attempts to model this system have suggested that the evolution of resistance may drive gypsy moth outbreaks. Thus, it seems likely that the evolution of resistance and fluctuating population densities are key to understanding the interaction between the gypsy moth and its virus, while the evolution of pathogen virulence may be important largely because it helps to maintain variability in host resistance. This research will investigate the following questions: Does host resistance drive population outbreaks in the gypsy moth? How is variability in host resistance maintained? The approach to answer these questions will be to document changes in host resistance and pathogen virulence in several outbreaking gypsy moth populations, during the period while these populations are collapsing because of virus epidemics. In addition, we will quantify additive genetic variability in virus resistance in the gypsy moth, to understand the potential for evolutionary changes in this insect. Also, we will explore whether host-pathogen specificity and/or fitness tradeoffs in host and pathogen can help to maintain host resistance. This will serve to unite the two previously disparate fields of population dynamics and evolutionary dynamics, and may shed light on strategies to manage this pest insect.