Microevolution and population dynamics of Prochlorococcus cells in the ocean: Insights through single-cell genomics

海洋中原绿球藻细胞的微进化和种群动态：通过单细胞基因组学的见解

• 批准号: 1145734
• 负责人: Sallie Chisholm
• 金额: $ 30万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-15 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1145734&HistoricalAwards=false
• 关键词: Microevolution; population; dynamics; Prochlorococcus; cells

Prochlorococcus is a bacterium that is widespread and abundant in the world oceans. As a photosynthetic cell, it uses sunlight to fix carbon dioxide into organic carbon, similar to plants on land. The global Prochlorococcus population in the oceans is made up of a diversity of "ecotypes," each of which has slightly different conditions for optimal growth. It is hypothesized that the diversity of this group of microbes allows it to thrive over broadly varying ocean habitats, but the genetic underpinnings of this diversity is very poorly understood. This research aims at advancing our understanding of the ecology and evolution of Prochlorococcus, by studying the genetic composition of single wild Prochlorococcus cells isolated from the Atlantic and Pacific oceans at different times of year. The study is motivated by two fundamental questions: (i) what is the relationship between the genetic composition of the cells and their ecological dynamics? (ii) how do populations adapt to their environment over ecological and evolutionary time scales?The broader significance of this work lies in the central role that Prochlorococcus plays in ocean ecology and the global carbon cycle. As the most abundant photosynthetic group in the oceans, Prochlorococcus is a critical component of the base of the food web. Because it conducts a sizable fraction of ocean photosynthesis, it plays an important role in the global carbon cycle and global climate processes. Understanding what regulates Prochlorococcus' diversity and dynamics is critical for developing predictive models of these important Earth system features.

原氯球菌是一种广泛存在于世界海洋中的细菌。作为一种光合作用细胞，它利用阳光将二氧化碳固定为有机碳，类似于陆地上的植物。全球海洋中的原氯球菌群由多种“生态型”组成，每种生态型的最佳生长条件略有不同。据推测，这组微生物的多样性使其能够在广泛不同的海洋栖息地中茁壮成长，但这种多样性的遗传基础却知之甚少。本研究旨在通过对分离自大西洋和太平洋不同时间段的单个野生原氯球菌细胞的遗传组成的研究，加深对原氯球菌生态学和进化的认识。这项研究的动机是两个基本问题：(I)细胞的遗传组成与它们的生态动态之间有什么关系？(2)种群如何在生态和进化的时间尺度上适应其环境？这项工作的更广泛的意义在于原氯球菌在海洋生态和全球碳循环中发挥的中心作用。作为海洋中最丰富的光合作用基团，原氯球菌是食物链基础的重要组成部分。由于它进行了相当大一部分海洋光合作用，它在全球碳循环和全球气候过程中发挥着重要作用。了解是什么控制了原氯球菌的多样性和动态，对于开发这些重要的地球系统特征的预测模型至关重要。