Editorial overview: Microbial manipulation of insect-parasite interactions
Editorial overview: Microbial manipulation of insect-parasite interactions
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编辑概述：昆虫与寄生虫相互作用的微生物操纵
DOI：
10.1016/j.cois.2019.04.005
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发表时间：
2019
影响因子：
5.3
通讯作者：
Oliver, KM
中科院分区：
文献类型：
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作者：
Oliver, KM
长期以来，寄主-寄生虫的相互作用一直令生物学家着迷，因为它们是功能和分类多样性的驱动力。如果进化生物学家JBS Haldane(1964年出生)当时就知道今天所知道的，他可能会取笑神灵对寄生虫的过度喜爱，因为寄生蜂的数量可能远远超过最初被吹捧为受欢迎动物的甲虫[1]。如果这个数字修正被传递到更早的时间，那么达尔文可能传达了一个更深刻的怀疑。达尔文说过一句著名的话：我无法说服自己，一个仁慈而无所不能的上帝会故意创造出姬蜂科，其明确的意图是在毛虫的活体内喂养它们。随着分类学的多样性，寄生虫使用的看似险恶、当然也是怪异的策略不断扩大，它们提供捕食者和寄生虫来寻找、制服并经常杀死它们不幸的宿主。反过来，这些在宿主中产生了多样化的抵抗性免疫反应和行为，以避免或生存攻击，以及随后宿主-寄生虫共同进化的可能性。越来越多人认识到的另一层阴谋是，许多相互对抗的宏观相互作用的结果是由隐蔽的微生物介导的。长期以来，动物和微生物之间的共生一直被认为是功能新颖性的来源[3]，感染共生体可能会带来新的特征，这些特征会改变对立的相互作用结果，有利于它们各自的宿主。因此，当面临共同的寄生威胁时，昆虫可能会与微生物结盟；寄生虫可能会与共生体合作，以提高攻击成功。在陆地系统中，自19世纪以来，人们一直在研究大型生物之间的防御性互惠关系(如植物与蚂蚁的食草性防御)[4]。然而，直到后来发现许多草本植物具有产生生物碱的真菌内生菌来防御草食性疾病后，才广泛认识到微生物介导的宏观相互作用[5]。据我所知，第一个潜在的以寄生虫为靶标的共生体保护昆虫宿主的报告涉及感染沃尔巴克氏菌的紫花苜蓿象甲[6]。在这种情况下，抗生素治疗的象甲极大地提高了它们对寄生虫的敏感性，这表明寄主相关的细菌，尽管沃尔巴克氏菌从未被证实是负责的病原体。这项研究在很大程度上被忽视了，因为它缺乏关键的细节，并且在沃尔巴克氏菌的许多保护作用被发现之前浮出水面[7]。然而，在接下来的几年里，各种细菌共生体被证明可以保护各种昆虫免受捕食者、病原体、寄生虫和寄生虫的侵害[8-11]。一般来说，共生体通过对宿主免疫系统的影响来提供防御[12，13]，与天敌竞争有限的资源[14，15]，或者通过产生直接伤害敌人的抗菌剂和毒素[16，17]。防御性共生的最新和最新研究试图描述
Host–parasite interactions have long fascinated biologists as drivers of functional and taxonomic diversity. If evolutionary biologist JBS Haldane (d. 1964) knew then what is known today, he might instead have quipped about the deity’s ‘inordinate fondness for parasitoids’ as parasitic wasps may substantially outnumber the beetles originally touted as favored beasts [1]. If this numerical revision was transported further back in time, then Darwin, who famously said ‘I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of caterpillars’[2] may have conveyed an even more profound doubt. As along with taxonomic diversity comes an ever-expanding repertoire of seemingly sinister and certainly bizarre tactics wielded by parasites, provisioning predators and parasitoids to find, subdue, and often kill their unfortunate hosts. In turn these yield a diversity of countervailing immune responses and behaviors in hosts to avoid or survive attack, as well the potential for ensuing host–parasite coevolution. An increasingly recognized additional layer of intrigue is that the outcomes of many antagonistic macro-interactions are mediated by covert microorganisms. Symbioses between animals and microbes have long been recognized as sources of functional novelty [3] and infection with symbionts may bring novel traits that sway antagonistic interaction outcomes in favor of their respective hosts. Hence insects may align with microbes when facing a shared threat of parasitism; and parasites may collaborate with symbionts to improve attack success.In terrestrial systems, defensive mutualisms between macro-organisms (eg plants defended against herbivory by ants) have been studied since the 19th century [4]. However, macro-interactions mediated by microbes became widely appreciated only later upon discovery that many grasses have alkaloid-producing fungal endophytes that defend against herbivory [5]. To my knowledge, the first report of a potential parasite-targeting symbiont defending an insect host involved Wolbachia-infected alfalfa weevils [6]. In this case, antibiotic curing of weevils greatly improved their susceptibility to parasitism, which pointed to a host-associated bacterium, although Wolbachia was never confirmed to be the responsible agent. This study was largely overlooked because it lacked critical details and surfaced before the many protective roles of Wolbachia were discovered [7]. However, in the following years, diverse bacterial symbionts were shown to protect an assortment of insects against predators, pathogens, parasites and parasitoids [8–11]. In general, symbionts provide defense via effects on host immune systems [12, 13], competing with natural enemies for limiting resources [14, 15], or by producing antimicrobials and toxins that directly harm enemies [16, 17]. Recent and current studies in defensive symbiosis seek to characterize