Microbiome assemblages of plants and animals often show a degree of correlation with host phylogeny; an eco-evolutionary pattern known as phylosymbiosis. Using 16S rRNA gene sequencing to profile the microbiome, paired with COI, 18S rRNA and ITS1 host phylogenies, phylosymbiosis was investigated in four groups of coral reef invertebrates (scleractinian corals, octocorals, sponges and ascidians). We tested three commonly used metrics to evaluate the extent of phylosymbiosis: (a) intraspecific versus interspecific microbiome variation, (b) topological comparisons between host phylogeny and hierarchical clustering (dendrogram) of host-associated microbial communities, and (c) correlation of host phylogenetic distance with microbial community dissimilarity. In all instances, intraspecific variation in microbiome composition was significantly lower than interspecific variation. Similarly, topological congruency between host phylogeny and the associated microbial dendrogram was more significant than would be expected by chance across all groups, except when using unweighted UniFrac distance (compared with weighted UniFrac and Bray-Curtis dissimilarity). Interestingly, all but the ascidians showed a significant positive correlation between host phylogenetic distance and associated microbial dissimilarity. Our findings provide new perspectives on the diverse nature of marine phylosymbioses and the complex roles of the microbiome in the evolution of marine invertebrates.

中文翻译：

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多种珊瑚礁无脊椎动物表现出系统共生模式。


植物和动物的微生物组组合通常与宿主系统发育表现出一定程度的相关性。一种称为系统共生的生态进化模式。使用 16S rRNA 基因测序来分析微生物组，并与 COI、18S rRNA 和 ITS1 宿主系统发育配对，对四类珊瑚礁无脊椎动物（石珊瑚、八珊瑚、海绵和海鞘）的系统共生进行了研究。我们测试了三个常用的指标来评估系统共生的程度：（a）种内与种间微生物组变异，（b）宿主系统发育和宿主相关微生物群落的层次聚类（树状图）之间的拓扑比较，以及（c）宿主的相关性系统发育距离与微生物群落的差异。在所有情况下，微生物组组成的种内变异均显着低于种间变异。同样，宿主系统发育和相关微生物树状图之间的拓扑一致性比所有组中偶然预期的更显着，除非使用未加权的 UniFrac 距离（与加权 UniFrac 和 Bray-Curtis 相异性相比）。有趣的是，除了海鞘之外，所有其他动物的宿主系统发育距离和相关的微生物差异之间都表现出显着的正相关。我们的研究结果为海洋系统共生的多样性以及微生物组在海洋无脊椎动物进化中的复杂作用提供了新的视角。