Inbreeding-related trade-offs in stress-resistance in the ant Formica exsecta

Inbred individuals and populations are predicted to suffer from inbreeding depression, especially in times of stress. Under natural conditions, organisms are exposed to more than one stressor at any one time, highlighting the importance of stress resistance traits. We studied how inbreeding- and immunity-related traits are correlated under different dietary conditions in the ant Formica exsecta. Its natural diet varies in the amount and nature of plant secondary compounds and the level of free radicals, all of which require detoxification to maintain organismal homeostasis. We found that inbreeding decreased general antibacterial activity under dietary stress, suggesting inbreeding-related physiological trade-offs.近交个体及种群预计会遭受近交衰退（inbreeding depression），且该效应在应激环境中尤为突出。自然条件下，生物通常会同时面临多种胁迫因子，这凸显了抗胁迫性状的重要性。本研究以蚂蚁Formica exsecta为研究对象，探究了不同饮食条件下近交相关性状与免疫相关性状的关联模式。该物种的天然食谱中，植物次生代谢物（plant secondary compounds）的含量与种类、以及自由基（free radicals）水平均存在差异，所有此类物质均需通过解毒作用（detoxification）以维持机体稳态（organismal homeostasis）。研究结果显示，在饮食胁迫条件下，近交作用会降低机体的整体抗菌活性（antibacterial activity），这表明存在与近交相关的生理权衡（physiological trade-offs）。