Ravigné Virginie, Becker Nathalie, Massol François, Guichoux Erwan, Boury Christophe, Mahé Frédéric, Facon Benoit
CIRAD UMR PHIM Montpellier France.
PHIM Univ Montpellier CIRAD INRAE Institut Agro IRD Montpellier France.
Evol Appl. 2022 May 3;15(10):1621-1638. doi: 10.1111/eva.13352. eCollection 2022 Oct.
One promising avenue for reconciling the goals of crop production and ecosystem preservation consists in the manipulation of beneficial biotic interactions, such as between insects and microbes. Insect gut microbiota can affect host fitness by contributing to development, host immunity, nutrition, or behavior. However, the determinants of gut microbiota composition and structure, including host phylogeny and host ecology, remain poorly known. Here, we used a well-studied community of eight sympatric fruit fly species to test the contributions of fly phylogeny, fly specialization, and fly sampling environment on the composition and structure of bacterial gut microbiota. Comprising both specialists and generalists, these species belong to five genera from to two tribes of the Tephritidae family. For each fly species, one field and one laboratory samples were studied. Bacterial inventories to the genus level were produced using 16S metabarcoding with the Oxford Nanopore Technology. Sample bacterial compositions were analyzed with recent network-based clustering techniques. Whereas gut microbiota were dominated by the Enterobacteriaceae family in all samples, microbial profiles varied across samples, mainly in relation to fly identity and sampling environment. Alpha diversity varied across samples and was higher in the Dacinae tribe than in the Ceratitinae tribe. Network analyses allowed grouping samples according to their microbial profiles. The resulting groups were very congruent with fly phylogeny, with a significant modulation of sampling environment, and with a very low impact of fly specialization. Such a strong imprint of host phylogeny in sympatric fly species, some of which share much of their host plants, suggests important control of fruit flies on their gut microbiota through vertical transmission and/or intense filtering of environmental bacteria.
协调作物生产目标与生态系统保护目标的一个有前景的途径在于操纵有益的生物相互作用，比如昆虫与微生物之间的相互作用。昆虫肠道微生物群可通过促进发育、宿主免疫、营养或行为来影响宿主健康。然而，包括宿主系统发育和宿主生态学在内的肠道微生物群组成和结构的决定因素仍知之甚少。在此，我们利用一个经过充分研究的由八种同域果蝇物种组成的群落，来测试果蝇系统发育、果蝇专一性以及果蝇采样环境对细菌肠道微生物群组成和结构的影响。这些物种既有专性物种也有广性物种，属于实蝇科两个族的五个属。对于每种果蝇，我们研究了一个野外样本和一个实验室样本。使用牛津纳米孔技术通过16S元条形码技术生成属水平的细菌清单。用最近基于网络的聚类技术分析样本细菌组成。尽管所有样本中的肠道微生物群均以肠杆菌科为主，但微生物谱在不同样本中有所不同，主要与果蝇种类和采样环境有关。α多样性在不同样本中有所变化，在果实蝇族中高于小条实蝇族。网络分析允许根据微生物谱对样本进行分组。得到的组与果蝇系统发育非常一致，采样环境有显著调节作用，而果蝇专一性的影响非常小。在同域果蝇物种中宿主系统发育有如此强烈的印记，其中一些物种共享许多宿主植物，这表明果蝇通过垂直传播和/或对环境细菌的强烈过滤对其肠道微生物群有重要控制作用。
