Fight or flight? - Flight increases immune gene expression but does not help to fight an infection

Flight represents a key trait in most insects, being energetically extremely demanding, yet often necessary for foraging and reproduction. Additionally, dispersal via flight is especially important for species living in fragmented landscapes. Even though, based on life-history theory, a negative relationship may be expected between flight and immunity, a number of previous studies have indicated flight to induce an increased immune response. In this study, we assessed whether induced immunity (i.e. immune gene expression) in response to 15min forced flight treatment impacts individual survival of bacterial infection in the Glanville fritillary butterfly (Melitaea cinxia). We were able to confirm previous findings of flight induced immune gene expression, but still observed substantially stronger effects on both gene expression levels and lifespan due to bacterial infection compared to flight treatment. Even though gene expression levels of some immunity-related genes were elevated due t...飞行是多数昆虫的核心性状之一，尽管其能量消耗极高，却常是觅食与繁殖的必要条件。此外，依靠飞行完成扩散，对于栖息于破碎化生境中的物种尤为关键。尽管根据生活史理论（life-history theory），飞行与免疫之间可能存在负相关关系，但此前已有多项研究证实，飞行可引发免疫应答增强。本研究以格兰维尔贝母蝶（Melitaea cinxia）为实验材料，探究了15分钟强制飞行处理所诱导的免疫反应（即免疫基因表达）是否会影响个体在细菌感染后的存活率。我们成功验证了此前关于飞行可诱导免疫基因表达的研究结论，但相较于飞行处理，细菌感染对基因表达水平与寿命的影响仍显著更强。尽管部分免疫相关基因的表达水平因……