Experimental demonstration of a parasite-induced immune response in wild birds: Darwin's finches and introduced nest flies.
Experimental demonstration of a parasite-induced immune response in wild birds: Darwin's finches and introduced nest flies.
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DOI：
10.1002/ece3.651
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发表时间：
2013-08
影响因子：
2.6
通讯作者：
Clayton, Dale H.
中科院分区：
文献类型：
--
作者：
Koop, Jennifer A. H.;Owen, Jeb P.;Knutie, Sarah A.;Aguilar, Maria A.;Clayton, Dale H.
生态免疫学旨在解释宿主之间免疫防御的强度和效力的差异。然而，一个缺点是在自然条件下未能将宿主免疫反应与实际寄生虫联系起来。在这里，我们提出了一个寄生虫诱导的免疫反应在野生鸟类种群的第一个实验演示之一。最近引进的体外寄生巢蝇Philornis downsi严重影响了加拉帕戈斯群岛达尔文雀和其他陆地鸟类的健康。早期的一项研究表明，雌性中型地雀（Geospiza fortis）具有与羽绒肺孢子虫结合的抗体，这与苍蝇暴露随时间的推测变化相关。在目前的研究中，我们实验性地操纵了苍蝇的数量，以测试苍蝇是否真的会引起抗体水平的变化。我们操纵P. downsi丰富的巢和定量P. downsi结合抗体水平的中型地面雀的母亲，父亲，和雏鸟。我们还量化了宿主行为，如梳理，这可以与抗体介导的防御体外寄生虫。Philornis downsi结合抗体水平显着较高的母亲在寄生巢，相比（熏蒸）nonparasitized巢的母亲。抗体水平较高的母亲往往在巢穴中有较少的寄生虫，这表明抗体在防御寄生虫方面发挥作用。母亲们没有表现出增强免疫反应有效性的行为变化。无论是成年雄性，还是雏鸟，都没有唐氏疟原虫诱导的免疫或行为反应，这将增强对苍蝇的防御。尽管母亲有免疫反应，但没有一个被寄生的巢穴能生出任何后代。因此，这项研究表明，虽然母亲的免疫反应似乎是防御性的，但它不足以挽救当前的生殖健康。这项研究进一步表明了测试免疫防御的适应性后果的重要性，而不是假设这种反应会增加宿主的适应性。宿主的免疫反应可以防止寄生的负面健身后果;然而，这些反应的强度和有效性在宿主之间存在差异。强的宿主免疫反应通常被认为与更大的宿主适应性相关。本研究以达尔文雀与一种侵入性巢内寄生虫，探讨宿主免疫反应、寄生虫负荷与宿主适合度之间的关系。我们发现，虽然母亲的免疫反应似乎是防御性的，但它并没有拯救当前的生殖健康。
Ecological immunology aims to explain variation among hosts in the strength and efficacy of immunological defenses. However, a shortcoming has been the failure to link host immune responses to actual parasites under natural conditions. Here, we present one of the first experimental demonstrations of a parasite-induced immune response in a wild bird population. The recently introduced ectoparasitic nest fly Philornis downsi severely impacts the fitness of Darwin's finches and other land birds in the Galápagos Islands. An earlier study showed that female medium ground finches (Geospiza fortis) had P. downsi-binding antibodies correlating with presumed variation in fly exposure over time. In the current study, we experimentally manipulated fly abundance to test whether the fly does, in fact, cause changes in antibody levels. We manipulated P. downsi abundance in nests and quantified P. downsi-binding antibody levels of medium ground finch mothers, fathers, and nestlings. We also quantified host behaviors, such as preening, which can integrate with antibody-mediated defenses against ectoparasites. Philornis downsi-binding antibody levels were significantly higher among mothers at parasitized nests, compared to mothers at (fumigated) nonparasitized nests. Mothers with higher antibody levels tended to have fewer parasites in their nests, suggesting that antibodies play a role in defense against parasites. Mothers showed no behavioral changes that would enhance the effectiveness of the immune response. Neither adult males, nor nestlings, had P. downsi-induced immunological or behavioral responses that would enhance defense against flies. None of the parasitized nests fledged any offspring, despite the immune response by mothers. Thus, this study shows that, while the immune response of mothers appeared to be defensive, it was not sufficient to rescue current reproductive fitness. This study further shows the importance of testing the fitness consequences of immune defenses, rather than assuming that such responses increase host fitness. Host immune responses can protect against the negative fitness consequences of parasitism; however, the strength and effectiveness of these responses vary among hosts. Strong host immune responses are often assumed to correlate with greater host fitness. This study investigates the relationship between host immune response, parasite load, and host fitness using Darwin's finches and an invasive nest parasite. We found that while the immune response of mothers appeared defensive, it did not rescue current reproductive fitness.
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影响因子：
3.7
作者：
Huber SK;Owen JP;Koop JA;King MO;Grant PR;Grant BR;Clayton DH
通讯作者：
Clayton DH
影响因子：
2.5
作者：
Christe, P;Richner, H;Oppliger, A
通讯作者：
Oppliger, A
影响因子：
1.5
作者：
Dudaniec, RY;Kleindorfer, S;Fessl, B
通讯作者：
Fessl, B
影响因子：
2.7
作者：
Dvorak, M;Vargas, H;Tebbich, S
通讯作者：
Tebbich, S
影响因子：
5.9
作者：
Huber, Sarah K.
通讯作者：
Huber, Sarah K.