Communication between microorganisms in the marine environment has immense ecological impact by mediating trophic-level interactions and thus determining community structure ¹ . Extracellular vesicles (EVs) are produced by bacteria ^2,3 , archaea ⁴ , protists ⁵ and metazoans, and can mediate pathogenicity ⁶ or act as vectors for intercellular communication. However, little is known about the involvement of EVs in microbial interactions in the marine environment ⁷ . Here we investigated the signalling role of EVs produced during interactions between the cosmopolitan alga Emiliania huxleyi and its specific virus (EhV, Phycodnaviridae) ⁸ , which leads to the demise of these large-scale oceanic blooms ^9,10 . We found that EVs are highly produced during viral infection or when bystander cells are exposed to infochemicals derived from infected cells. These vesicles have a unique lipid composition that differs from that of viruses and their infected host cells, and their cargo is composed of specific small RNAs that are predicted to target sphingolipid metabolism and cell-cycle pathways. EVs can be internalized by E. huxleyi cells, which consequently leads to a faster viral infection dynamic. EVs can also prolong EhV half-life in the extracellular milieu. We propose that EVs are exploited by viruses to sustain efficient infectivity and propagation across E. huxleyi blooms. As these algal blooms have an immense impact on the cycling of carbon and other nutrients ^11,12 , this mode of cell-cell communication may influence the fate of the blooms and, consequently, the composition and flow of nutrients in marine microbial food webs.

中文翻译：

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通过细胞外囊泡的通讯增强了大都会藻类的病毒感染。

海洋环境中微生物之间的交流通过介导营养级相互作用并因此决定了群落结构，对生态产生了巨大影响¹。细胞外囊泡（EVs）由细菌^2,3，古细菌⁴，原生生物⁵和后生动物产生，并可以介导致病性⁶或充当细胞间通讯的载体。但是，关于电动汽车参与海洋环境⁷中微生物相互作用的了解甚少。在这里，我们调查了国际大都会海藻Emiliaania huxleyi与它的特定病毒（EhV，Phycodnaviridae）之间的相互作用过程中产生的EV的信号传导作用⁸，这导致这些大规模的海洋大花灭绝^9,10。我们发现，电动汽车在病毒感染期间或旁观者细胞暴露于感染细胞衍生的信息化学物质时大量产生。这些囊泡具有独特的脂质成分，不同于病毒及其感染的宿主细胞，它们的货物由特定的小RNA组成，这些小RNA预计将靶向鞘脂代谢和细胞周期途径。电动车可以被赫氏大肠杆菌（E. huxleyi）细胞内化，从而导致更快的病毒感染动态。电动汽车还可以延长EhV在细胞外环境中的半衰期。我们建议电动汽车被病毒利用，以维持有效的感染力并在赫黎大花盛开期间传播。由于这些藻华对碳和其他养分的循环产生巨大影响^11,12 ，这种细胞间通讯方式可能会影响花朵的命运，进而影响海洋微生物食物网中养分的组成和流动。