Pearman William S, Duffy Grant A, Smith Robert O, Currie Kim I, Gemmell Neil J, Morales Sergio E, Fraser Ceridwen I
Department of Marine Science, University of Otago, Dunedin, New Zealand.
Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.
Nat Commun. 2024 Dec 30;15(1):10759. doi: 10.1038/s41467-024-54954-z.
What little we know about how microbiomes change over the course of host dispersal has been gleaned from simulations or snapshot sampling of microbiomes of hosts undertaking regular, cyclical migrations. These studies suggest that major changes in both microbiome richness and turnover occur in response to long-distance movements, but we do not yet know how rare or sporadic dispersal events for non-migratory organisms might affect the microbiomes of their hosts. Here we directly examine the microbiomes of rafting seaweed, leveraging host genomic analyses, amplicon sequencing, and oceanographic modelling to study the impacts of ecological dispersal of hosts on their microbiomes. We find that once dislodged from coastal shores and adrift, kelp-associated microbial communities change profoundly-the core microbes found on attached kelp give way to a few abundant taxa and many rare taxa. Changes in microbial species richness and composition are strongly linked to variability in sea surface temperature rather than length of time spent rafting. These changes are associated with increased contributions of neutral processes shaping community assembly. These findings highlight the role of environmental predictability in triggering major community successional changes and challenge the importance of host selection in determining the microbiome.
我们对微生物群落在宿主扩散过程中如何变化的了解非常有限，这些了解是从对进行定期周期性迁徙的宿主微生物群的模拟或快照采样中获得的。这些研究表明，微生物群落丰富度和周转率的重大变化是对长距离移动的响应，但我们尚不知道非迁徙生物的罕见或零星扩散事件如何影响其宿主的微生物群落。在这里，我们直接研究漂浮海藻的微生物群，利用宿主基因组分析、扩增子测序和海洋学建模来研究宿主生态扩散对其微生物群的影响。我们发现，一旦从海岸脱落并漂流，与海带相关的微生物群落就会发生深刻变化——附着在海带表面的核心微生物被一些丰富的分类群和许多罕见的分类群所取代。微生物物种丰富度和组成的变化与海面温度的变化密切相关，而不是与漂流时间的长短相关。这些变化与塑造群落组装的中性过程的贡献增加有关。这些发现突出了环境可预测性在引发主要群落演替变化中的作用，并对宿主选择在决定微生物群落方面的重要性提出了挑战。
