Zhang Fan, Berg Maureen, Dierking Katja, Félix Marie-Anne, Shapira Michael, Samuel Buck S, Schulenburg Hinrich
Alkek Center for Metagenomics and Microbiome Research, Baylor College of Medicine Houston, TX, USA.
Department of Integrative Biology, University of California, Berkeley Berkeley, CA, USA.
Front Microbiol. 2017 Mar 23;8:485. doi: 10.3389/fmicb.2017.00485. eCollection 2017.
The nematode is used as a central model system across biological disciplines. Surprisingly, almost all research with this worm is performed in the absence of its native microbiome, possibly affecting generality of the obtained results. In fact, the microbiome had been unknown until recently. This review brings together results from the first three studies on microbiomes, all published in 2016. Meta-analysis of the data demonstrates a considerable conservation in the composition of the microbial communities, despite the distinct geographical sample origins, study approaches, labs involved and perturbations during worm processing. The microbiome is enriched and in some cases selective for distinct phylotypes compared to corresponding substrate samples (e.g., rotting fruits, decomposing plant matter, and compost soil). The dominant bacterial groups include several (, and ) and . They are consistently joined by several rare putative keystone taxa like . The bacteria are able to enhance growth of nematode populations, as well as resistance to biotic and abiotic stressors, including high/low temperatures, osmotic stress, and pathogenic bacteria and fungi. The associated microbes thus appear to display a variety of effects beneficial for the worm. The characteristics of these effects, their relevance for fitness, the presence of specific co-adaptations between microbiome members and the worm, and the molecular underpinnings of microbiome-host interactions represent promising areas of future research, for which the advantages of as an experimental system should prove of particular value.
线虫被用作跨生物学科的核心模型系统。令人惊讶的是，几乎所有对这种蠕虫的研究都是在其原生微生物群缺失的情况下进行的，这可能会影响所获结果的普遍性。事实上，直到最近线虫的微生物群才为人所知。这篇综述汇集了2016年发表的关于线虫微生物群的前三项研究结果。对数据的荟萃分析表明，尽管地理样本来源、研究方法、涉及的实验室以及线虫处理过程中的干扰各不相同，但微生物群落的组成仍有相当程度的保守性。与相应的底物样本（如腐烂的水果、分解的植物物质和堆肥土壤）相比，线虫微生物群在某些情况下对不同的系统发育型具有富集和选择性。主要的细菌类群包括几种伯克氏菌属（伯克氏菌、椰酵假单胞菌和洋葱伯克霍尔德菌）和假单胞菌属。它们始终与几种罕见的假定关键类群如嗜麦芽窄食单胞菌相伴。这些细菌能够促进线虫种群的生长，以及增强对生物和非生物应激源的抗性，包括高温/低温、渗透胁迫以及致病细菌和真菌。因此，相关微生物似乎对线虫显示出多种有益作用。这些作用的特点、它们对线虫适应性的相关性、微生物群成员与线虫之间特定共适应的存在以及微生物群与宿主相互作用的分子基础，代表了未来研究中很有前景的领域，对于这些领域而言，线虫作为实验系统的优势应会证明具有特殊价值。
