What makes a host profitable? Parasites balance host nutritive resources against immunity
What makes a host profitable? Parasites balance host nutritive resources against immunity
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DOI：
10.1086/523943
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发表时间：
2008-01-01
影响因子：
2.9
通讯作者：
Roulin, Alexandre
中科院分区：
文献类型：
--
作者：
Bize, Pierre;Jeanneret, Caroline;Roulin, Alexandre
许多宿主的品质可以调节寄生虫的健身，其中，宿主的营养资源和免疫力是最重要的。事实上，寄生虫适应性随着从宿主体内提取的营养资源的量而增加，并随着宿主免疫反应而减少。因此，为了最大限度地提高适应性，寄生虫必须平衡这两种宿主成分。然而，由于宿主的营养资源和免疫力都随着宿主身体状况的增加而增加，目前还不清楚寄生虫在主要，中间或不良状况下对宿主的表现是否更好。我们调查了血粉大小和生存的体外寄生虱苍蝇Melaerina Melaerina的身体状况和皮肤的免疫反应，他们的高山雨燕（Apus melba）雏鸟宿主。虱蝇采取了较小的血餐，生活在一个较短的时间内喂养的雏鸟，实验性的食物剥夺或有他们的皮肤免疫反应与蛋氨酸增强。与这些结果相一致，虱蝇生存率是最高的非实验雏鸟在中间体条件下喂养时。我们的研究结果强调，虽然在条件差的主机有一个降低的免疫能力，寄生虫可能会避免他们，因为在条件差的个人没有提供足够的资源。这些发现突出了这样一个事实，即给予宿主免疫能力的主要考虑可能导致对宿主-寄生虫相互作用的有偏见的评价。
Numerous host qualities can modulate parasite fitness, and among these, host nutritive resources and immunity are of prime importance. Indeed, parasite fitness increases with the amount of nutritive resources extracted from the host body and decreases with host immune response. To maximize fitness, parasites have therefore to balance these two host components. Yet, because host nutritive resources and immunity both increase with host body condition, it is unclear whether parasites perform better on hosts in prime, intermediate, or poor condition. We investigated blood meal size and survival of the ectoparasitic louse fly Crataerina melbae in relation to body condition and cutaneous immune response of their Alpine swift (Apus melba) nestling hosts. Louse flies took a smaller blood meal and lived a shorter period of time when feeding on nestlings that were experimentally food deprived or had their cutaneous immune response boosted with methionine. Consistent with these results, louse fly survival was the highest when feeding on nonexperimental nestlings in intermediate body condition. Our findings emphasize that although hosts in poor condition had a reduced immunocompetence, parasites may have avoided them because individuals in poor condition did not provide adequate resources. These findings highlight the fact that giving host immunocompetence primary consideration can result in a biased appraisal of host-parasite interactions.