Department of Chemistry, Environmental Microbiology and Biotechnology (EMB), University of Duisburg-Essen, Universitätsstraße 5, 45141 Essen, Germany.
Institute for Chemistry and Biology of the Marine Environment (ICBM), Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26111 Oldenburg, Germany.
Viruses. 2021 Oct 21;13(11):2126. doi: 10.3390/v13112126.
Viruses are the most abundant biological entities on Earth with an estimate of 10 viral particles across all ecosystems. Prokaryotic viruses-bacteriophages and archaeal viruses-influence global biogeochemical cycles by shaping microbial communities through predation, through the effect of horizontal gene transfer on the host genome evolution, and through manipulating the host cellular metabolism. Imaging techniques have played an important role in understanding the biology and lifestyle of prokaryotic viruses. Specifically, structure-resolving microscopy methods, for example, transmission electron microscopy, are commonly used for understanding viral morphology, ultrastructure, and host interaction. These methods have been applied mostly to cultivated phage-host pairs. However, recent advances in environmental genomics have demonstrated that the majority of viruses remain uncultivated, and thus microscopically uncharacterized. Although light- and structure-resolving microscopy of viruses from environmental samples is possible, quite often the link between the visualization and the genomic information of uncultivated prokaryotic viruses is missing. In this minireview, we summarize the current state of the art of imaging techniques available for characterizing viruses in environmental samples and discuss potential links between viral imaging and environmental genomics for shedding light on the morphology of uncultivated viruses and their lifestyles in Earth's ecosystems.
病毒是地球上最丰富的生物实体，据估计，所有生态系统中都有 10 亿个病毒粒子。原核病毒——噬菌体和古菌病毒——通过捕食作用、水平基因转移对宿主基因组进化的影响以及操纵宿主细胞代谢来塑造微生物群落，从而影响全球生物地球化学循环。成像技术在了解原核病毒的生物学和生活方式方面发挥了重要作用。具体来说，结构解析显微镜方法，例如透射电子显微镜，常用于了解病毒的形态、超微结构和宿主相互作用。这些方法主要应用于培养的噬菌体-宿主对。然而，环境基因组学的最新进展表明，大多数病毒仍然未被培养，因此在显微镜下无法表征。尽管可以对环境样本中的病毒进行光镜和结构解析，但在可视化和未培养原核病毒的基因组信息之间经常存在缺失的联系。在这篇综述中，我们总结了用于表征环境样本中病毒的成像技术的最新进展，并讨论了病毒成像与环境基因组学之间的潜在联系，以揭示未培养病毒的形态及其在地球生态系统中的生活方式。
