Viral infections are major modulators of marine microbial community assembly and biogeochemical cycling. In coral reefs, viral lysis controls bacterial overgrowth that is detrimental to coral health. However, methodological limitations have prevented the identification of viral hosts and quantification of their interaction frequencies. Here, we reconstructed an abundance-resolved virus-bacteria interaction network in the oligotrophic coral reef waters of Curaçao by integrating direct microscopy counts with virus-host links obtained from proximity-ligation, prophage integration, and CRISPR spacers. This network of 3,013 individual links (97 unique species-level interactions) revealed that the abundance of free viral particles was weakly related to host abundance and viral production, as indicated by the cell-associated virus-to-host ratio. The viruses with the highest free and cell-associated virus-to-host ratio, interpreted here as highly productive viruses, formed links with intermediate-to-low abundance hosts belonging to Gammaproteobacteria, Bacteroidia, and Planctomycetia. In contrast, low-production viruses interacted with abundant members of Alphaproteobacteria and Gammaproteobacteria enriched in prophages. These findings highlight the decoupling between viral abundance and production and identify potentially active viruses. We propose that differential decay rates and burst sizes may explain the decoupling between free viral abundance and production and that lysogenic infections play an important role in the ecology of high-abundance hosts.

中文翻译：

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珊瑚礁上的宿主特异性病毒捕食网络


病毒感染是海洋微生物群落组装和生物地球化学循环的主要调节因子。在珊瑚礁中，病毒裂解控制了对珊瑚健康有害的细菌过度生长。然而，方法学上的局限性阻碍了病毒宿主的鉴定和其相互作用频率的量化。在这里，我们通过将直接显微镜计数与通过邻近连接、原噬菌体整合和 CRISPR 垫片获得的病毒-宿主链接相结合，在库拉索岛的寡营养珊瑚礁水域重建了一个丰度解析的病毒-细菌相互作用网络。这个由 3,013 个单独链接（97 个独特的物种水平相互作用）组成的网络揭示了游离病毒颗粒的丰度与宿主丰度和病毒产生呈弱相关，如细胞相关病毒与宿主的比率所示。具有最高游离和细胞相关病毒与宿主比的病毒，在这里被解释为高产病毒，与属于 γ 变形菌门、拟杆菌属和浮霉菌属的中低丰度宿主形成联系。相比之下，低产量病毒与富含原噬菌体的 Alpha 变形菌门和 Gammaproteobacteria 的丰富成员相互作用。这些发现突出了病毒丰度和生产之间的脱钩，并确定了潜在的活性病毒。我们提出，不同的衰变速率和爆发大小可以解释游离病毒丰度和产生之间的脱钩，并且溶原感染在高丰度宿主的生态学中起着重要作用。