School of Oceanography, University of Washington, Seattle, WA, USA.
Department of Biochemistry, University of Washington, Seattle, WA, USA.
Nat Microbiol. 2020 Aug;5(8):1011-1015. doi: 10.1038/s41564-020-0725-x. Epub 2020 May 18.
Host-virus interactions structure microbial communities, drive biogeochemical cycles and enhance genetic diversity in nature. Hypotheses proposed to explain the range of interactions that mediate these processes often invoke lysogeny, a latent infection strategy used by temperate bacterial viruses to replicate in host cells until an induction event triggers the production and lytic release of free viruses. Most cultured bacteria harbour temperate viruses in their genomes (prophage). The absence of prophages in cultures of the dominant lineages of marine bacteria has contributed to an ongoing debate over the ecological significance of lysogeny and other viral life strategies in nature. Here, we report the discovery of prophages in cultured SAR11, the ocean's most abundant clade of heterotrophic bacteria. We show the concurrent production of cells and viruses, with enhanced virus production under carbon-limiting growth conditions. Evidence that related prophages are broadly distributed in the oceans suggests that similar interactions have contributed to the evolutionary success of SAR11 in nutrient-limited systems.
宿主-病毒相互作用构建了微生物群落，驱动了生物地球化学循环，并增强了自然界中的遗传多样性。为了解释介导这些过程的一系列相互作用，提出了各种假说，这些假说常常涉及溶原性，即温和噬菌体在宿主细胞中复制的潜伏感染策略，直到诱导事件触发游离病毒的产生和裂解释放。大多数培养的细菌在其基因组（原噬菌体）中携带温和噬菌体。海洋细菌优势谱系的培养物中缺乏原噬菌体，这导致了关于溶原性和自然中其他病毒生活策略的生态意义的持续争论。在这里，我们报告了在培养的 SAR11 中发现原噬菌体，SAR11 是海洋中最丰富的异养细菌类群。我们展示了细胞和病毒的同时产生，以及在碳限制生长条件下增强的病毒产生。有关原噬菌体广泛分布于海洋的证据表明，类似的相互作用促进了 SAR11 在营养限制系统中的进化成功。
