Ecology and Evolution of Arctic Marine Microbial Communities

北极海洋微生物群落的生态和进化

• 批准号: RGPIN-2022-05280
• 负责人: Collins, Eric
• 金额: $ 2.04万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=753232
• 关键词: Ecology; Evolution; Arctic; Marine; Microbial

The defining characteristic of the Arctic Ocean is the thin layer of sea ice that has covered its surface more or less continuously for tens of millions of years. Marine microbes in Arctic seawater and sea ice (including bacteria, archaea, fungi, protists, algae, and viruses) have had millions of years to adapt to the extreme conditions there, including perennially subzero temperatures, high brine salinity, and long periods of extended darkness and daylight. However, in the last 40 years, that ice cover has started to melt. Arctic sea ice extent and volume have both declined precipitously, resulting in increased interests in shipping, exploration, and resource extraction in the now seasonally ice-free waters. While the Arctic Ocean is changing faster than any other environment on Earth, our observational efforts have not kept up. However, recent advances in high-throughput DNA sequencing have allowed the possibility of observing microbial communities at temporal and spatial scales that were unimaginable only a generation ago. The long term goal of my Discovery program is to take advantage of novel sequencing technologies to contribute to ecological and evolutionary models of Arctic marine microbial communities from an Ecosystem Services perspective, advancing our understanding of the effects of past, current and future climatic changes on these bellweather ecosystems. The specific Objectives of this 5-year Discovery proposal are (1) to identify genomic indicators of functional adaptation in microbial populations, and (2) to provide novel insights into microbial community succession in sea ice and seawater over numerous time scales. Objective (1) will lead to improvements in evolutionary models of Arctic marine microbes by greatly increasing the number of complete genomes available from these environments. Using long-read nanopore sequencing technology will enable the assembly of many closed, circular genomes for cold-adapted bacteria and archaea, which will be used to assess evolutionary models of functional and cold adaptation through comparative genomics, and insights into the role that horizontal gene transfer plays. Objective (2) will lead to improvements in ecological models of Arctic marine ecosystems by greatly increasing the temporal resolution by which community succession can be observed, which is typically sparse due to logistical difficulties. However, I will make use of a new Arctic research facility located on Hudson Bay, the Churchill Marine Observatory (CMO). This facility will provide year-round access to cold seawater, enabling high-temporal-resolution models of seawater microbial succession in response to temperature, salinity, light, nutrients, and ice dynamics. Likewise, I will obtain sea ice grown in large mesocosm tanks at CMO (10m x 10m x 3m) for analysis of rapid changes in microbial community structure resulting from freezing and melting dynamics, which have already been substantially altered by climate warming.

北极海洋的定义特征是蛋白质或多或少地覆盖了北极海水和海冰的海洋微生物（倾斜细菌，阿彻，真菌，真菌，生物，藻类和病毒）的野生微生物的覆盖范围或多或少。但是，在过去的40年中，冰覆盖量已经融化了，这是北极海冰的延长和日光。在地球上的任何其他eTron都没有保持更快的速度。要利用新型的测序技术来为来自生态系统服务的北极海洋微生物群落的生态和进化模型做出贡献，从而使我们对过去的效果的理解有所了解，年度发现建议的特殊性是（1）识别微生物群体的基因组指示剂海冰和海水中的埃斯在许多时间尺度上（1）将通过大量增加来自环境的完整基因组来改善北极海洋微生物的进化模型。这将是通过比较基因组学的进化模型，以及北极海洋生态系统的水平基因转移模型将利用位于哈德逊湾的新北极研究设施，该设施在寒冷的季节中主要通行，从而使海水微生物继任的高速型模型可响应CMO的温度，盐度，养分和冰罐（10m x 10m x 3M）用于分析由冻结和熔化动态导致微生物群落的快速变化，而气候变暖已经大大改变了Alreatady。