High-resolution genomics to reveal changes in microbial biodiversity across space and time in the warming Arctic Ocean

高分辨率基因组学揭示北冰洋变暖中微生物生物多样性随空间和时间的变化

• 批准号: NE/W005654/1
• 负责人: Thomas Mock
• 金额: $ 60.1万
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW005654%2F1
• 关键词: resolution; genomics; reveal; changes; microbial

The Arctic is the most impacted ecosystem on Earth by global warming. Thus, it serves as a bellwether for the consequences of global change and therefore the persistence of biodiversity on our planet. Yet, due to logistical challenges to access, the Arctic and especially the central Arctic Ocean, remains one of the most poorly understood biomes on Earth. Moreover, as the environmental change in the Arctic is accelerating, it has become the main focus of geopolitical interests because the Arctic is not only regulating global climate but is used for extracting biological and geological resources. Thus, the Arctic provides significant ecosystem services on biodiversity that is largely unknown, particularly for the most inaccessible geographic areas such as the central Arctic Ocean. Understanding how the largest of all aquatic ecosystems in the Arctic changes is therefore crucial for different key disciplines of the 21st century including climate research, conservation, and sustainable economic development. Aquatic microbes in sea ice and seawater play pivotal roles in climate feedbacks and in sustaining food webs (marine primary production), which are central for conservation and ecosystem services. Microbes also serve as biological indicators due to their fast adaptive response following environmental change. Although genomic approaches have provided transformative insights into responses of microbial communities to environmental change, their application is limited in polar ecosystems and especially the central Arctic Ocean mainly due to issues of access and the extreme nature of this ecosystem. To overcome these challenges, a Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) has been conducted in 2020. MOSAiC is the largest polar expedition in history including over 20 countries with more than 400 researchers, studying a drifting surface habitat while it crosses the central Arctic Ocean via the transpolar drift current. Hence, the ice-breaker RV 'Polarstern' spent a year drifting across the central Arctic Ocean and locked up into the sea ice. This expedition, therefore, enabled for the first time to sample the same surface-ocean habitat (mainly sea ice and co-drifting water directly underneath) while it was carried across the Arctic Ocean by the transpolar drift current. Thus, the MOSAiC drift expedition has created a time series of samples reflecting the seasonal cycle of environmental changes in a drifting surface ocean habitat (e.g. a sea-ice floe from its formation to thaw), which is unprecedented but will help to reveal how the environmental change in the Arctic Ocean impacts the Arctic climate system. This new NERC project is not only built on the unique time-series data and samples, it capitalizes on a subsequent microbial genomics project funded by the DOE Joint Genome Institute (JGI, USA). The latter is providing sequence data including their basic analyses (e.g. assembly, annotations) of microbial metagenomes and metatranscriptomes for over 400 time-series samples from the drifting sea-ice floe. Bespoke bioinformatics and community ecology analyses will be applied to those sequence data for revealing how habitat-specific genomic diversity of ocean microbes and their microbiomes is changing throughout time (complete seasonal cycle) and in relation to changing habitat characteristics (e.g. formation of sea ice in autumn and thaw in spring and summer). Thus, this project will provide a baseline for assessing how microbes as a biological bellwether respond to the changing Arctic Ocean, which is essential for making predictions about how warming in the Arctic impacts ecosystem services underpinned by microbes such as sustaining the marine food web and driving the carbon cycle in the Arctic Ocean.

通过全球变暖，北极是地球上影响最大的生态系统。因此，它是全球变化后果以及生物多样性在我们星球上的持久性的领域。然而，由于进入后勤挑战，北极，尤其是北极中心的海洋仍然是地球上最知名的生物群落之一。此外，随着北极环境变化正在加速，它已成为地缘政治利益的主要重点，因为北极不仅在调节全球气候，而且用于提取生物学和地质资源。因此，北极在生物多样性上提供了重要的生态系统服务，这在很大程度上是未知的，尤其是对于最不可接受的地理区域，例如中央北极海洋。因此，了解北极变化中所有水生生态系统中最大的最大生态系统如何对于21世纪的不同关键学科至关重要，包括气候研究，保护和可持续的经济发展。海冰和海水中的水生微生物在气候反馈和维持食物网（海洋初级生产）中扮演关键角色，这是保护和生态系统服务的核心。由于环境变化后，微生物还可以作为生物学指标。尽管基因组方法为微生物群落对环境变化的反应提供了变革性的见解，但它们的应用在极地生态系统中，尤其是北极海洋中的中央海洋受到限制，这主要是由于该生态系统的通道和极端性质。为了克服这些挑战，在2020年进行了多学科的漂流观测站（Mosaic）。Mosaic是历史上最大的极地探险，其中包括20多个拥有400多名研究人员的国家，研究了一个漂流的表面栖息地，而它通过传输层流横切了北极海洋，而北极海洋横穿了北极海洋。因此，破冰的RV“ Polarstern”花了一年的时间在北极中部的海洋中漂流，并锁定在海冰中。因此，这次探险是首次启用了相同的地表海栖息地（主要是海冰和直接在下面的水）进行采样，而后极漂移电流将其横穿北极海洋。因此，马赛克漂移探险创建了一个时间序列的样本，反映了漂流地面海洋栖息地中环境变化的季节性周期（例如，从其形成到融化的海冰浮动），这是前所未有的，但将有助于揭示北极海洋中环境变化如何影响北极气候系统。这个新的NERC项目不仅建立在独特的时间序列数据和样本上，还利用了由DOE联合基因组研究所（JGI，美国）资助的随后的微生物基因组学项目。后者提供了序列数据，其中包括其基本分析（例如组装，注释）对来自漂流的Sea-Ice Floe的400多个时间序列样本的微生物元基因组和元转录组。定制的生物信息学和社区生态学分析将应用于那些序列数据，以揭示海洋微生物及其微生物组的栖息地特异性基因组多样性如何在整个时间（完整的季节性周期）变化，并且与不断变化的栖息地特征有关（例如，春季和夏季的海冰形成）。因此，该项目将提供一个基准，用于评估微生物作为生物膜如何应对不断变化的北极海洋的反应，这对于预测北极中的变暖如何影响由微生物支撑的生态系统服务（例如维持海洋食品网络和驱动北极海洋碳循环）的生态系统服务至关重要。