Bad guys turned nice? A critical assessment of Wolbachia mutualisms in arthropod hosts
Bad guys turned nice? A critical assessment of Wolbachia mutualisms in arthropod hosts
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DOI：
10.1111/brv.12098
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发表时间：
2015-02-01
影响因子：
10
通讯作者：
Hammerstein, Peter
中科院分区：
文献类型：
--
作者：
Zug, Roman;Hammerstein, Peter
沃尔巴克氏体是节肢动物中最丰富的细菌内共生体。尽管是母系遗传，但它们并不符合垂直传播不可避免地选择有益共生体的普遍观点。相反，沃尔巴克氏体因其生殖寄生而臭名昭著，虽然降低了宿主的适应性，但确保了它们的传播。然而，即使对于生殖寄生虫来说，它也可以增强宿主的适应性。事实上，最近有关沃尔巴克氏体相关健身益处的报道激增。因此，问题就出现了，这种互利共生的实例如何与生殖寄生的表型相关。在这里，我们回顾了节肢动物中沃尔巴克氏体互利共生的证据，包括兼性关系和专性关系，并批判性地评估了它们的生物学相关性。尽管许多研究报告了沃尔巴克氏体的抗病原体作用，但很少有人真正证明这些作用与现场条件相关。我们进一步表明，沃尔巴克氏体经常同时产生有益和有害的影响，并且生殖操作和专性互利共生可能具有共同的机制。这些发现破坏了沃尔巴克氏体互利共生和寄生之间明确区分的想法。一般来说，兼性和专性共生都会对沃尔巴克氏体及其节肢动物宿主的生态和进化产生强烈的、有时是不可预见的影响。承认这种互利共生的潜力可能是更好地理解沃尔巴克氏体与宿主相互作用研究中一些未解决问题的关键。
Wolbachia are the most abundant bacterial endosymbionts among arthropods. Although maternally inherited, they do not conform to the widespread view that vertical transmission inevitably selects for beneficial symbionts. Instead, Wolbachia are notorious for their reproductive parasitism which, although lowering host fitness, ensures their spread. However, even for reproductive parasites it can pay to enhance host fitness. Indeed, there is a recent upsurge of reports on Wolbachia-associated fitness benefits. Therefore, the question arises how such instances of mutualism are related to the phenotypes of reproductive parasitism. Here, we review the evidence of Wolbachia mutualisms in arthropods, including both facultative and obligate relationships, and critically assess their biological relevance. Although many studies report anti-pathogenic effects of Wolbachia, few actually prove these effects to be relevant to field conditions. We further show that Wolbachia frequently have beneficial and detrimental effects at the same time, and that reproductive manipulations and obligate mutualisms may share common mechanisms. These findings undermine the idea of a clear-cut distinction between Wolbachia mutualism and parasitism. In general, both facultative and obligate mutualisms can have a strong, and sometimes unforeseen, impact on the ecology and evolution of Wolbachia and their arthropod hosts. Acknowledging this mutualistic potential might be the key to a better understanding of some unresolved issues in the study of Wolbachia-host interactions.