Chaplinska Mariia, Gerritsma Sylvia, Dini-Andreote Francisco, Falcao Salles Joana, Wertheim Bregje
Evolutionary Genetics, Development & Behaviour, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.
Genomics Research in Ecology and Evolution in Nature, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.
PLoS One. 2016 Dec 14;11(12):e0167726. doi: 10.1371/journal.pone.0167726. eCollection 2016.
In Drosophila, diet is considered a prominent factor shaping the associated bacterial community. However, the host population background (e.g. genotype, geographical origin and founder effects) is a factor that may also exert a significant influence and is often overlooked. To test for population background effects, we characterized the bacterial communities in larvae of six genetically differentiated and geographically distant D. melanogaster lines collected from natural populations across Europe. The diet for these six lines had been identical for ca. 50 generations, thus any differences in the composition of the microbiome originates from the host populations. We also investigated whether induced shifts in the microbiome-in this case by controlled antibiotic administration-alters the hosts' resistance to parasitism. Our data revealed a clear signature of population background on the diversity and composition of D. melanogaster microbiome that differed across lines, even after hosts had been maintained at the same diet and laboratory conditions for over 4 years. In particular, the number of bacterial OTUs per line ranged from 8 to 39 OTUs. Each line harboured 2 to 28 unique OTUs, and OTUs that were highly abundant in some lines were entirely missing in others. Moreover, we found that the response to antibiotic treatment differed among the lines and significantly altered the host resistance to the parasitoid Asobara tabida in one of the six lines. Wolbachia, a widespread intracellular endosymbiont associated with parasitoid resistance, was lacking in this line, suggesting that other components of the Drosophila microbiome caused a change in host resistance. Collectively, our results revealed that lines that originate from different population backgrounds show significant differences in the established Drosophila microbiome, outpacing the long-term effect of diet. Perturbations on these naturally assembled microbiomes to some degree influenced the hosts' resistance against natural parasites.
在果蝇中，饮食被认为是塑造相关细菌群落的一个重要因素。然而，宿主种群背景（如基因型、地理起源和奠基者效应）也是一个可能产生重大影响但经常被忽视的因素。为了测试种群背景效应，我们对从欧洲各地自然种群中收集的六个遗传分化且地理距离较远的黑腹果蝇品系的幼虫中的细菌群落进行了表征。这六个品系的饮食在大约50代中一直相同，因此微生物组组成的任何差异都源于宿主种群。我们还研究了微生物组的诱导变化——在这种情况下是通过控制抗生素给药——是否会改变宿主对寄生的抵抗力。我们的数据揭示了种群背景对黑腹果蝇微生物组的多样性和组成有明显影响，不同品系之间存在差异，即使宿主在相同饮食和实验室条件下维持了4年以上。特别是，每个品系的细菌OTU数量从8到39个不等。每个品系含有2到28个独特的OTU，一些品系中高度丰富的OTU在其他品系中完全缺失。此外，我们发现各品系对抗生素治疗的反应不同，并且在六个品系之一中显著改变了宿主对寄生蜂塔氏阿索巴蜂的抵抗力。该品系缺乏与寄生抗性相关的广泛存在的细胞内共生菌沃尔巴克氏体，这表明果蝇微生物组的其他成分导致了宿主抗性的变化。总体而言，我们的结果表明，来自不同种群背景的品系在已建立的果蝇微生物组中表现出显著差异，超过了饮食的长期影响。对这些自然组装的微生物组的扰动在一定程度上影响了宿主对自然寄生虫的抗性。
