University of Bern, Zoological Institute, Division of Evolutionary Ecology, Wohlenstrasse 50a, CH-3032 Hinterkappelen, Switzerland E-mail:
Evolution. 2012 Mar;66(3):732-739. doi: 10.1111/j.1558-5646.2011.01506.x. Epub 2011 Dec 8.
Why do individuals have an imperfect immune system? Most studies suggest trade-offs associated with immunity and metabolism, and neglect ecological factors, such as predation. We provide one of the first experimental studies demonstrating a context-dependent survival cost to immune activation. In the presence of a predator, immune-challenged male field crickets showed significantly lower survival than controls, whilst there was no difference in a predator-free environment. Immune-challenged males spent more time outside their burrows and reacted slower to a simulated predator attack. We conclude that some costs of immunity are expressed via increased susceptibility to predation, indicating the importance of integrating the ecological context when investigating optimal investment in immunity.
为什么个体的免疫系统并不完美？大多数研究表明，免疫和代谢之间存在权衡，而忽略了捕食等生态因素。我们提供了首个实验研究之一，证明免疫激活与生存之间存在依赖于环境的代价。在存在捕食者的情况下，受到免疫挑战的雄性蟋蟀的存活率明显低于对照组，而在没有捕食者的环境中则没有差异。受到免疫挑战的雄性蟋蟀在洞穴外的时间更多，对模拟捕食者的攻击反应更慢。我们的结论是，免疫的一些代价通过增加对捕食的易感性表现出来，这表明在研究免疫的最佳投资时，纳入生态环境的重要性。
