Immune activity suppresses reproduction in food-limited female tree lizards Urosaurus ornatus
Immune activity suppresses reproduction in food-limited female tree lizards Urosaurus ornatus
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DOI：
10.1111/j.1365-2435.2007.01311.x
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发表时间：
2007-12-01
影响因子：
5.2
通讯作者：
Moore, M. C.
中科院分区：
文献类型：
--
作者：
French, S. S.;Johnston, G. I. H.;Moore, M. C.
1.当资源稀缺时，生物体面临着试图优化相互竞争的功能的关键挑战。繁殖和免疫功能都是资源密集型的，对大多数物种来说都很重要。大多数研究都报告了生殖过程中免疫功能的下调。相反，目前还不清楚免疫反应是否会影响生殖过程，而且很少有研究研究这两个过程之间的资源竞争。在这里，我们报道了在脊椎动物模型系统树蜥蜴(Urosaurus Ornatus)中生殖系统和免疫系统之间直接竞争资源的证据。我们控制了生殖雌性树蜥蜴的食物摄入量，其中一半的雌性蜥蜴正在进行皮肤伤口愈合，另一半没有。然后，我们测量了所有动物的生殖投资和所有受伤动物的伤口愈合率。我们发现，不受限制地获取食物的动物既能维持生殖功能又能维持免疫功能，而限制饮食的动物则不能。具体地说，当食物不受限制时，雌性能够投资于繁殖并治愈她们的伤口。然而，当食物有限时，被迫愈合皮肤伤口的女性的毛囊比没有受伤的女性要小得多。在极度食物限制(即没有食物)的情况下，生殖投资和伤口愈合都受到抑制。这些结果清楚地证明了生殖系统和免疫系统之间的资源竞争，即只有在资源有限的情况下，才会出现这两个系统之间的生理权衡。此外，这种兼性调节是可调节的，允许动物对不断变化的环境条件做出反应。
1. When resources are scarce, organisms are faced with critical challenges trying to optimize competing functions. Reproduction and immune function are both resource intensive and important to most species. Most studies have reported a down-regulation of immune function during reproduction. Conversely, it is unclear whether mounting an immune response can affect the reproductive process and few studies have examined competition for resources between these two processes.2. Here we report evidence for direct competition for resources between the reproductive and immune systems in a vertebrate model system, the tree lizard (Urosaurus ornatus). We manipulated food intake in reproductive female tree lizards, where half of the females were undergoing cutaneous wound healing and the other half were not. We then measured reproductive investment in all animals and wound healing rate in all wounded animals.3. We found that animals with unlimited access to food sustained both reproduction and immune function whereas animals maintained on a restricted diet were not. Specifically, when food was unlimited, females were able to invest in reproduction and heal their wounds. However, when food was limited, females forced to heal a cutaneous wound had significantly smaller follicles than their non-wounded counterparts. Under extreme food limitation (i.e. no food) both reproductive investment and wound healing were suppressed.4. These results clearly demonstrate resource competition between the reproductive and immune systems, whereby physiological trade-offs between the two systems only arise when resources are limiting. Furthermore, this type of facultative regulation is adjustable and allows animals to respond to changing environmental conditions.