Single Cell Genome Sequencing of Uncultured Prokaryotes From the South Atlantic Mesopelagic

海洋的中远洋区位于海面以下200至1000米，约占全球海洋体积的25%。它拥有地球上最大的生态系统之一，也是人们最不了解的生态系统之一。这个区域接收从光带落下的有机物质，并由微生物主导，微生物的活动对海洋生产力至关重要——因为它们循环养分——对全球碳循环也至关重要。这个群体也构成了尚未开发的药品来源。尽管人们对这一深海生物群落有相当大的兴趣，但中深海微生物的生物化学、生理学和进化历史仍然是一个谜，这主要是由于该地区的巨大规模和研究工具的局限性。作为研究这些深海生物群落的新方法，毕格罗海洋科学实验室的科学家们将采用单扩增基因组学（SAG），这是一种新颖的变革性技术，可以重建从环境中收集的未培养微生物的整个基因组。这些科学家将SAG与用于细胞分选的流式细胞术结合起来，将这一过程应用于海洋。这项技术是革命性的，因为尽管许多海洋细菌是不可培养的，但这一限制现在被克服了，因为它允许这些科学家研究微生物（通过其基因组），而不需要首先将有机体带入培养。这些研究人员将使用来自南大西洋环流中上层区的样本，并通过仔细的筛选程序，从这些样本中产生数百个sag，然后可以对其进行测序。这些研究人员将特别感兴趣的是描述参与复杂生物分子降解和控制海洋生产力的氮化合物转化的微生物的特征和基因组组成。这些SAG序列还将与宏基因组序列数据集（如全球海洋调查数据集）进行比对，以推测这些生物的代谢、生理和进化历史。这些科学家将从未培养的细胞中收集到的基因组信息将为未来的微生物进化和群体遗传学研究奠定基础。为了促进这项新技术的发展和更广泛的应用，研究人员将邀请博士后和本科生参与该项目，主持SAG研讨会，并建立一个基于网络的SAG讨论组。SAG基因组序列文库也将成为一个重要的社区资源。

The mesopelagic zone of the ocean is 200 to 1000 m below the sea surface and contains about 25% of the global ocean volume. It harbors one of the largest and least understood of the Earth's ecosystems. This region receives the organic matter which rains down from the photic zone and is dominated by microorganisms whose activities are critical for ocean productivity - because they recycle nutrients - and for the global carbon cycle. This community also constitutes an untapped source of pharmaceuticals. Despite considerable interest in this deep-dwelling community, the biochemistry, physiology and evolutionary history of mesopelagic microbes remain enigmatic, largely due to access, the vast scale of the region and the limitations of research tools. As a new approach to the study of these deep dwelling communities, scientists at the Bigelow Laboratory for Ocean Sciences will employ single amplified genomics (SAG), a novel, transformative technology which enables the reconstruction of the entire genome of an uncultured microorganism collected from the environment. These scientists coupled SAG with flow cytometry, which is used for sorting cells, to apply this procedure in the ocean. This technology is transformative because, though many marine bacteria are not culturable, this limitation is now overcome because it allows these scientists to study a microbe (through its genome) without the need for first bringing the organism into culture. These investigators will use samples from the mesopelagic zone in the South Atlantic Gyre and through a careful screening procedure, produce hundreds of SAGs from these samples, which can then be sequenced. These researchers will be particularly interested in characterizing the identities and genomic composition of the microorganisms which are involved in the degradation of complex biomolecules and in the transformations of nitrogen compounds that control the productivity of the ocean. These SAG sequences will also be interrogated with metagenomic sequence datasets, such as the Global Ocean Survey dataset, to postulate the metabolism, physiology and evolutionary history of these organisms. The genomic information these scientists will gather from uncultured cells will lay the groundwork for microbial evolution and population genetics studies in the future. To promote development and broader use of this new technology, the investigators will be engaging postdoctoral associates and undergraduate students in the project, hosting SAG workshops, and establishing a web-based SAG discussion group. The SAG genome sequence library will also be an important community resource.