Abstract:
Microbial species that comprise host-associated microbiomes play an essential role in maintaining and mediating the health of plants and animals. While defining the role of individual or even complex communities is important toward quantifying the effect of the microbiome on host health, it is often challenging to develop causal studies that link microbial populations to changes in host fitness. Here, we investigated the impacts of reduced microbial load following antibiotic exposure on the fitness of the anemone, Exaiptasia diaphana and subsequent recovery of the host\'s microbiome. Anemones were exposed to two different types of antibiotic solutions for 3 weeks and subsequently held in sterilized seawater for a 3-week recovery period. Our results revealed that both antibiotic treatments reduced the overall microbial load during and up to 1 week post-treatment. The observed reduction in microbial load was coupled with reduced anemone biomass, halted asexual reproduction rates, and for one of the antibiotic treatments, the partial removal of the anemone\'s algal symbiont. Finally, our amplicon sequencing results of the 16S rRNA gene revealed that anemone bacterial composition only shifted in treated individuals during the recovery phase of the experiment, where we also observed a significant reduction in the overall diversity of the microbial community. Our work implies that the E. diaphana\'s microbiome contributes to host fitness and that the recovery of the host\'s microbiome following disturbance with antibiotics leads to a reduced, but stable microbial state.IMPORTANCEExaiptasia diaphana is an emerging model used to define the cellular and molecular mechanisms of coral-algal symbioses. E. diaphana also houses a diverse microbiome, consisting of hundreds of microbial partners with undefined function. Here, we applied antibiotics to quantify the impact of microbiome removal on host fitness as well as define trajectories in microbiome recovery following disturbance. We showed that reduction of the microbiome leads to negative impacts on host fitness, and that the microbiome does not recover to its original composition while held under aseptic conditions. Rather the microbiome becomes less diverse, but more consistent across individuals. Our work is important because it suggests that anemone microbiomes play a role in maintaining host fitness, that they are susceptible to disturbance events, and that it is possible to generate gnotobiotic individuals that can be leveraged in microbiome manipulation studies to investigate the role of individual species on host health.
摘要:
包含宿主相关微生物组的微生物物种在维持和介导植物和动物的健康中起着至关重要的作用。虽然定义个体或甚至复杂群落的作用对于量化微生物群对宿主健康的影响很重要,开发将微生物种群与宿主适应性变化联系起来的因果研究通常具有挑战性。这里,我们调查了抗生素暴露后微生物负荷减少对海葵适应性的影响,排泄物和随后的宿主微生物组恢复。将海葵暴露于两种不同类型的抗生素溶液中3周,然后在无菌海水中保持3周的恢复期。我们的结果表明,两种抗生素治疗都降低了治疗期间和长达1周的总体微生物负荷。观察到的微生物负荷的减少与海葵生物量的减少有关,停止无性繁殖率,对于其中一种抗生素治疗,部分去除海葵的藻类共生体。最后,我们对16SrRNA基因的扩增子测序结果表明,在实验的恢复期,海葵细菌组成仅在接受治疗的个体中发生改变,我们还观察到微生物群落的整体多样性显着减少。我们的工作表明,E.diaphana的微生物组有助于宿主的健康,并且在抗生素干扰后宿主微生物组的恢复导致减少,而是稳定的微生物状态。IMPORTANCEExaiptasiadiaphana是一种新兴的模型,用于定义珊瑚-藻类共生的细胞和分子机制。E.diaphana还拥有多样化的微生物组,由数百个功能不确定的微生物伙伴组成。这里,我们应用抗生素来量化微生物组去除对宿主适应性的影响,并确定干扰后微生物组恢复的轨迹.我们发现微生物组的减少会对宿主适应性产生负面影响,并且在无菌条件下保持时,微生物组不会恢复到其原始组成。相反,微生物组变得不那么多样化,但在个人之间更加一致。我们的工作很重要,因为它表明海葵微生物在维持宿主健康方面发挥作用,它们容易受到干扰事件的影响,并且有可能产生可在微生物组操纵研究中利用的微生物个体,以研究个体物种对宿主健康的作用。