More Is Not Always Better: Coinfections with Defensive Symbionts Generate Highly Variable Outcomes
More Is Not Always Better: Coinfections with Defensive Symbionts Generate Highly Variable Outcomes
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更多并不总是更好：与防御性共生体的混合感染会产生高度可变的结果
DOI：
10.1128/aem.02537-19
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发表时间：
2020
影响因子：
4.4
通讯作者：
Johnson, Karyn N.
中科院分区：
文献类型：
--
作者：
Weldon, S. R.;Russell, J. A.;Oliver, K. M.;Johnson, Karyn N.
动物相关的微生物是高度可变的，促成了一组多样的共生体介导的表型。鉴于宿主和共生体基因型及其相互作用可以影响跨环境的基于共生体的表型，因此健身结果可能存在广泛的变化。豌豆蚜是一种可遗传兼性共生体的寄主，在寄主防御中具有独特的作用。保护性表型已在很大程度上作为单一感染进行了研究，但豌豆蚜虫通常携带多种HFS物种，与基于偶然性的预期相比，特定组合可能会富集或耗尽。在这里，我们研究了单一感染与两种常见的HFS表现出可变的富集，抗寄生虫Hamiltonella defensa和抗病原体Regiella insecticola，在三个宿主基因型和环境的共同感染的后果。正如预期的那样，单一感染H。defensa或R.虫蚁对它们各自的目标提高了防御力。单次感染保护性H. defensa降低了蚜虫在没有敌人挑战的情况下的适合度，而R.虫生相对良性。然而，作为一种混合感染，R. insecticola ameliorated H.防御感染成本。共感染的蚜虫继续受到H. defensa，但保护作用被R.两个克隆中的昆虫。值得注意的是，H. defensa消除了病原体暴露后通过共感染R.昆虫生由于病原体孢子形成被R. insecticola在共感染蚜虫中的表现不佳，可能源于H.防御成本，而不是削弱防御。我们的研究结果揭示了一组复杂的共感染的结果，这可能部分解释自然感染模式，并表明，共生体为基础的表型可能不容易预测仅仅基于感染status.IMPORTANCE的超多样性节肢动物往往窝藏母系传播的细菌，保护天敌。在许多物种中，低多样性的可遗传共生体社区是常见的，为共生体之间的合作和冲突提供了机会，这可能会影响所提供的防御服务。使用豌豆蚜虫，防御共生模型，我们表明，共同感染两种常见的防御共生体，antipathogenRegiella和antiparasiteHamiltonella，产生的结果是高度可变的相比，单一感染，始终保护指定的敌人。与单一感染相比，混合感染往往降低防御服务在敌人的挑战，但提高蚜虫健身在没有敌人。因此，多个共生体的感染并不一定会产生具有“瑞士军刀”防御众多敌人的多面手蚜虫。相反，共生体的特定组合可能会因为各种原因而受到青睐，包括当敌人不存在时，它们能够减少其他防御共生体的成本。
Animal-associated microbes are highly variable, contributing to a diverse set of symbiont-mediated phenotypes. Given that host and symbiont genotypes, and their interactions, can impact symbiont-based phenotypes across environments, there is potential for extensive variation in fitness outcomes. Pea aphids, Acyrthosiphon pisum, host a diverse assemblage of heritable facultative symbionts (HFS) with characterized roles in host defense. Protective phenotypes have been largely studied as single infections, but pea aphids often carry multiple HFS species, and particular combinations may be enriched or depleted compared to expectations based on chance. Here, we examined the consequences of single infection versus coinfection with two common HFS exhibiting variable enrichment, the antiparasitoid Hamiltonella defensa and the antipathogen Regiella insecticola, across three host genotypes and environments. As expected, single infections with either H. defensa or R. insecticola raised defenses against their respective targets. Single infections with protective H. defensa lowered aphid fitness in the absence of enemy challenge, while R. insecticola was comparatively benign. However, as a coinfection, R. insecticola ameliorated H. defensa infection costs. Coinfected aphids continued to receive antiparasitoid protection from H. defensa, but protection was weakened by R. insecticola in two clones. Notably, H. defensa eliminated survival benefits conferred after pathogen exposure by coinfecting R. insecticola. Since pathogen sporulation was suppressed by R. insecticola in coinfected aphids, the poor performance likely stemmed from H. defensa-imposed costs rather than weakened defenses. Our results reveal a complex set of coinfection outcomes which may partially explain natural infection patterns and suggest that symbiont-based phenotypes may not be easily predicted based solely on infection status.IMPORTANCEThe hyperdiverse arthropods often harbor maternally transmitted bacteria that protect against natural enemies. In many species, low-diversity communities of heritable symbionts are common, providing opportunities for cooperation and conflict among symbionts, which can impact the defensive services rendered. Using the pea aphid, a model for defensive symbiosis, we show that coinfections with two common defensive symbionts, the antipathogenRegiellaand the antiparasiteHamiltonella, produce outcomes that are highly variable compared to single infections, which consistently protect against designated enemies. Compared to single infections, coinfections often reduced defensive services during enemy challenge yet improved aphid fitness in the absence of enemies. Thus, infection with multiple symbionts does not necessarily create generalist aphids with “Swiss army knife” defenses against numerous enemies. Instead, particular combinations of symbionts may be favored for a variety of reasons, including their abilities to lessen the costs of other defensive symbionts when enemies are not present.
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影响因子：
4
作者：
Brisson, Jennifer A.;Stern, David L.
通讯作者：
Stern, David L.
影响因子：
4.9
作者：
Martinez, Adam J.;Weldon, Stephanie R.;Oliver, Kerry M.
通讯作者：
Oliver, Kerry M.
防御性内共生体的级联效应。
影响因子：
5.3
作者：
Ailsa H. C. McLean
通讯作者：
Ailsa H. C. McLean
美国东半部豌豆蚜 Acyrthosiphon pisum 的蚜虫寄生虫
DOI：
--
发表时间：
1977
期刊：
影响因子：
--
作者：
G. W. Angalet;R. Fuester
通讯作者：
R. Fuester
影响因子：
8.8
作者：
Graham, Robert I.;Grzywacz, David;Wilson, Kenneth
通讯作者：
Wilson, Kenneth