The native microbiome of the nematode Caenorhabditis elegans: gateway to a new host-microbiome model.
The native microbiome of the nematode Caenorhabditis elegans: gateway to a new host-microbiome model.
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DOI：
10.1186/s12915-016-0258-1
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发表时间：
2016-05-09
期刊：
影响因子：
5.4
通讯作者：
Schulenburg H
中科院分区：
文献类型：
--
作者：
Dirksen P;Marsh SA;Braker I;Heitland N;Wagner S;Nakad R;Mader S;Petersen C;Kowallik V;Rosenstiel P;Félix MA;Schulenburg H
宿主-微生物联合是宿主发育、免疫和生活史的许多关键过程的基础。然而，目前对中心模式物种秀丽线虫的研究都没有考虑到这种蠕虫的自然微生物群。取而代之的是，几乎所有的实验室都只使用标准菌株n2及其衍生的突变体，这些突变体通过以大肠杆菌菌株为食物的单氧菌培养中的常规漂白灭菌来保持。在这里，我们首次描述了线虫的本土微生物群，并评估了它对线虫生活史特征的影响。直接从其自然栖息地采集的线虫携带着物种丰富的细菌群落，以变形杆菌为主，如肠杆菌科和假单胞菌属、营养狭窄性单胞菌属、Ochrobactrum属和鞘氨醇单胞菌属。线虫的微生物群不同于蠕虫的自然环境和同属物种雷曼线虫。暴露在衍生的实验微生物组中，发现细菌组成受到宿主发育阶段和基因的影响。这些实验还表明，这些微生物在标准和压力条件下(例如，高温和低渗透压或高渗透压)都能增强宿主的适应性。利用线虫的透明度，我们进一步证明了几种变形杆菌能够进入线虫的肠道，Ochrobactrum分离物甚至似乎能够在压力条件下持续存在于肠道中。此外，三个假单胞菌分离株在体外产生了抗真菌的作用，我们表明这有助于蠕虫在体内对真菌病原体的防御。首次对线虫的本地微生物组进行的系统分析揭示了一个与线虫有关的物种丰富的细菌群落，这对于我们理解线虫的生物学可能具有核心重要性。所获得的信息和现在可用于实验工作的微生物分离株建立了线虫作为深入剖析宿主-微生物组相互作用的易于处理的模型。本文的在线版本(doi：10.1186/s12915-0160258-1)包含补充材料，授权用户可以使用。
Host-microbe associations underlie many key processes of host development, immunity, and life history. Yet, none of the current research on the central model species Caenorhabditis elegans considers the worm’s natural microbiome. Instead, almost all laboratories exclusively use the canonical strain N2 and derived mutants, maintained through routine bleach sterilization in monoxenic cultures with an E. coli strain as food. Here, we characterize for the first time the native microbiome of C. elegans and assess its influence on nematode life history characteristics. Nematodes sampled directly from their native habitats carry a species-rich bacterial community, dominated by Proteobacteria such as Enterobacteriaceae and members of the genera Pseudomonas, Stenotrophomonas, Ochrobactrum, and Sphingomonas. The C. elegans microbiome is distinct from that of the worm’s natural environment and the congeneric species C. remanei. Exposure to a derived experimental microbiome revealed that bacterial composition is influenced by host developmental stage and genotype. These experiments also showed that the microbes enhance host fitness under standard and also stressful conditions (e.g., high temperature and either low or high osmolarity). Taking advantage of the nematode’s transparency, we further demonstrate that several Proteobacteria are able to enter the C. elegans gut and that an Ochrobactrum isolate even seems to be able to persist in the intestines under stressful conditions. Moreover, three Pseudomonas isolates produce an anti-fungal effect in vitro which we show can contribute to the worm’s defense against fungal pathogens in vivo. This first systematic analysis of the nematode’s native microbiome reveals a species-rich bacterial community to be associated with C. elegans, which is likely of central importance for our understanding of the worm’s biology. The information acquired and the microbial isolates now available for experimental work establishes C. elegans as a tractable model for the in-depth dissection of host-microbiome interactions. The online version of this article (doi:10.1186/s12915-016-0258-1) contains supplementary material, which is available to authorized users.