Maternal pathogen exposure causes diet- and pathogen-specific transgenerational costs
Maternal pathogen exposure causes diet- and pathogen-specific transgenerational costs
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DOI：
10.1111/oik.03430
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发表时间：
2017
期刊：
影响因子：
3.4
通讯作者：
J. Littlefair;Alice M Laughton;R. Knell
中科院分区：
文献类型：
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作者：
J. Littlefair;Alice M Laughton;R. Knell
跨代效应，即父母经历的环境导致后代表型改变，现已在多种分类群中得到描述。在无脊椎动物中，关于这些影响的大部分研究都集中在亲代接触病原体或免疫引发剂在决定后代免疫投入或抗病性方面的作用。然而，迄今为止，无脊椎动物跨代效应的研究通常仅限于理想实验室环境中的单一感染或免疫诱导子。野外环境中的动物通常会经历次优环境以及多种寄生虫和病原体的共同感染，导致免疫投资的相对成本增加，并改变后代对亲本环境反应的健康益处。在这里，我们研究了一个更现实的生态场景，涉及多重感染和资源限制，使用印度谷螟作为模型宿主，用昆虫病原细菌苏云金芽孢杆菌和真菌白僵菌进行挑战。母亲接触低剂量的一种或两种病原体，或对照。每个家庭的后代都以优质或劣质食物喂养，然后暴露于一种或两种病原体。母亲接触病原体会导致后代对病原体的抵抗力降低，这取决于母体和后代病原体特异性感染的组合以及后代的资源限制。迄今为止，许多研究都集中在跨代免疫启动上，其中父母接触病原体或免疫引发剂会导致其后代的免疫反应上调。我们的系统中缺乏任何此类效应，这表明在亲本接触病原体后产生抵抗力较低的后代可能是一个重要的替代方案，其驱动因素是抵抗力成本而不是适应性益处。
Transgenerational effects, whereby the environment experienced by a parent leads to an altered offspring phenotype, have now been described in a variety of taxa. In invertebrates, much of the research on these effects has concentrated on the role of parental exposure to pathogens or immune elicitors in determining offspring immune investment or disease resistance. To date, however, studies of transgenerational effects in invertebrates have generally been restricted to single infections or immune elicitors in ideal laboratory environments. Animals in field situations will commonly experience sub‐optimal environments and co‐infection by multiple species of parasites and pathogens, leading to increased relative costs of immune investment and changing fitness benefits from offspring responses to the parental environment. Here we investigate a more ecologically realistic scenario involving both multiple infections and resource limitation, using the Indian meal mothPlodia interpunctellaas a model host, challenged with the entomopathogenic bacteriumBacillus thuringiensisand fungusBeauveria bassiana. Mothers were exposed to low doses of one or both pathogens, or a control. Offspring from each family were reared on either good‐ or poor‐quality food and then exposed to one or both pathogens. Maternal exposure to pathogens led to reduced pathogen resistance in offspring, depending on the combination of maternal and offspring pathogen‐specific infections and resource limitation in the offspring generation. Much research to date has focussed on trans‐generational immune priming, in which parental exposure to pathogens or immune elicitors leads to upregulated immune reactivity in their offspring. The lack of any such effects in our system suggests that the production of less resistant offspring following parental exposure to pathogens might be an important alternative, driven by costs of resistance rather than adaptive benefits.