Seiblitz I G L, Capel K C C, Oliveira R R, Zilberberg C, Cordeiro C A M M, Francini C L B, Zanotti A A, Ciotti A M, Kitahara M V
Center for Marine Biology, University of São Paulo, São Sebastião, SP, 11602-109, Brazil.
Graduate Program in Zoology, Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, SP, 05508-090, Brazil.
Environ Microbiome. 2025 Jun 14;20(1):71. doi: 10.1186/s40793-025-00725-2.
Diel and tidal rhythms can regulate the metabolism, physiology, behavior, and gene expression patterns of different organisms, with evidence of an integration on the circadian behavior of host species and their microbial community. Corals host a diverse and dynamic microbial community, with variable diversity and abundance across geographic and temporal scales. Within scleractinian corals, those that host endosymbiotic algae (i.e., zooxanthellate) display a diel variation in the oxygen levels, an oscillation in their internal environment that has the potential to influence its microbiome abundance and/or composition. Here we investigate in situ daily fluctuations on the microbial community of two zooxanthellate (Madracis decactis and Mussismilia hispida) and two azooxanthellate coral species (Tubastraea coccinea and T. tagusensis) along a 72-hour period.
Day and night alpha diversity values were similar for all species, with Ma. decactis hosting a significantly more diverse community. Similarly, there was no fluctuation in the microbiome composition at the Amplicon Sequence Variants (ASV) level between day and night within species, but all species were significantly different from each other. Interestingly, Mu. hispida, an endemic species to the Southwestern Atlantic, had a high proportion of unidentified microbial taxa at genus level, suggesting a species-specific microbiome community composed by unidentified taxa. Significant rhythmicity in the abundance of individual ASVs was observed for one ASV (genus Pseudoalteromonas) in T. tagusensis and one (genus Woeseia) in Ma. decactis, with 24 and 12-hour fluctuations, respectively. In addition, DESeq2 recovered 13 ASVs (four in Ma. decactis, two in Mu. hispida, six in T. coccinea, and one in T. tagusensis) with different abundances between day and night.
Results show divergent microbial communities when comparing zooxanthellate and azooxanthellate species, with few significant changes within a 24-hour period. Future studies should focus on metabolic pathways to better understand how the microbiome community can adjust to environmental changes within the coral host in short time scales.
昼夜节律和潮汐节律可以调节不同生物体的新陈代谢、生理机能、行为和基因表达模式，有证据表明宿主物种及其微生物群落的昼夜行为存在整合现象。珊瑚拥有多样且动态的微生物群落，其多样性和丰度在地理和时间尺度上存在差异。在石珊瑚中，那些宿主内共生藻类（即虫黄藻）的珊瑚，其氧含量呈现昼夜变化，这种内部环境的振荡有可能影响其微生物群落的丰度和/或组成。在此，我们研究了两种虫黄藻珊瑚（鹿角杯形珊瑚和希氏蔷薇珊瑚）以及两种非虫黄藻珊瑚物种（橙杯珊瑚和塔氏杯珊瑚）的微生物群落在72小时内的原位每日波动情况。
所有物种的昼夜α多样性值相似，鹿角杯形珊瑚的群落多样性显著更高。同样，在物种内部，扩增子序列变体（ASV）水平上的微生物群落组成在白天和夜晚之间没有波动，但所有物种彼此之间存在显著差异。有趣的是，西南大西洋的特有物种希氏蔷薇珊瑚在属水平上有很高比例的未鉴定微生物分类群，这表明其微生物群落是由未鉴定分类群组成的物种特异性群落。在塔氏杯珊瑚中观察到一个ASV（假交替单胞菌属）和鹿角杯形珊瑚中一个ASV（沃氏菌属）的丰度存在显著节律性，分别有24小时和12小时的波动。此外，DESeq2分析发现13个ASV（鹿角杯形珊瑚中有4个，希氏蔷薇珊瑚中有2个，橙杯珊瑚中有6个，塔氏杯珊瑚中有1个）在白天和夜晚的丰度不同。
结果表明，在比较虫黄藻珊瑚和非虫黄藻珊瑚物种时，微生物群落存在差异，且在24小时内几乎没有显著变化。未来的研究应聚焦于代谢途径，以更好地理解微生物群落如何在短时间尺度内适应珊瑚宿主内的环境变化。
