Evolution of Oxygenic Photosynthesis as Preserved in Melainabacterial Genomes from Lake Vanda, Antarctica

南极万达湖黑色细菌基因组中保存的产氧光合作用的进化

基本信息

批准号：
1745341
负责人：
Dawn Sumner
金额：
$ 32.39万
依托单位：
University of California-Davis
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-05-15 至 2022-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1745341&HistoricalAwards=false
关键词：
Evolution Oxygenic Photosynthesis Preserved Melainabacterial

项目摘要

Atmospheric oxygen rose suddenly approximately 2.4 billion years ago after Cyanobacteria evolved the ability to produce oxygen through photosynthesis (oxygenic photosynthesis). This change permanently altered the future of life on Earth, yet little is known about the evolutionary processes leading to it. The Melainabacteria were first discovered in 2013 and are closely related non-photosynthetic relatives of the first group of organisms capable of oxygenic photosynthesis. This project will utilize existing data on metagenomes from microbial mats in Lake Vanda, an ice-covered lake in Antarctica where many sequences of Melainabacteria have been previously identified. From this genetic information, the project aims to assess the metabolic capabilities of these Melainabacteria and identify their potential ecological roles. The project will additionally evaluate the evolutionary relationships among the Cyanobacteria and Melainabacteria and closely related organisms that will allow an advancement in understanding of the evolutionary path that lead to oxygenic photosynthesis on Earth. The project will focus on extracting evolutionary information from the genomic data of Melainabacteria and Sericytochromatia, recently-described groups closely related to but basal to the Cyanobacteria. The characterization of novel members of these groups in samples from Lake Vanda, Antarctica, will provide insights into the path and processes involved in the evolution of oxygenic photosynthesis. The research will focus on assessing the metabolic capabilities of Melainabacteri, deriving the evolutionary relationships among Melainabacteria and Cyanobacteria and reconstructing potential evolutionary pathways leading to oxygenic photosynthesis. The project will focus on 12 metagenomes where the researchers expect to obtain genomes for at least the eight most abundant Melainabacteria in the dataset. Melainabacteria bins will be annotated and preliminary metabolic pathways will be constructed. The project will utilize full-length sequences of marker genes from across the bacterial domain with a particular focus on taxa that are oxygenic or anoxygenic phototrophs and use the marker genes, to build a rooted "backbone" tree. Incomplete or short sequences from the metagenomes will be added to the tree using the Evolutionary Placement Algorithm. The researchers will also build a corresponding phylogenetic tree using a Bayesian framework and compare their topologies. By doing so, the project aims to improve the understanding of the evolution of oxygenic photosynthesis, which caused the most significant change in Earth's surface chemistry. Specifically, they will document a significantly broader metabolic diversity within the Melainabacteria than has been previously identified, gain significant insights into their metabolic evolution, their evolutionary relationships with the Cyanobacteria, and the evolutionary steps leading to the origin of oxygenic photosynthesis. This research will have the overall effect of constraining key evolutionary processes in the origin of oxygenic photosynthesis. It will provide the foundation for future studies by indicating where a genomic record of the evolution of oxygenic photosynthesis may be preserved. Results will also be shared with middle school children through the development of scientific lesson plans in collaboration with teachers.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

大约24亿年前，蓝藻进化出通过光合作用（产氧光合作用）产生氧气的能力后，大气中的氧气突然上升。这种变化永久地改变了地球上生命的未来，但人们对导致这种变化的进化过程知之甚少。黑色细菌于 2013 年首次被发现，是第一组能够进行产氧光合作用的生物体的非光合作用近亲。该项目将利用来自万达湖微生物垫的现有宏基因组数据，万达湖是南极洲的一个冰雪覆盖的湖泊，此前已在万达湖中鉴定出许多黑色细菌序列。该项目旨在根据这些遗传信息评估这些黑色杆菌的代谢能力并确定其潜在的生态作用。该项目还将评估蓝藻菌和黑藻菌以及密切相关的生物之间的进化关系，这将有助于加深对导致地球上产氧光合作用的进化路径的理解。该项目将侧重于从黑细菌和丝细胞染色菌的基因组数据中提取进化信息，最近描述的这些群体与蓝细菌密切相关但又是蓝细菌的基础。对来自南极洲万达湖的样本中这些类群的新成员进行表征，将有助于深入了解含氧光合作用演化的路径和过程。该研究将重点评估黑色杆菌的代谢能力，推导黑色杆菌和蓝藻之间的进化关系，并重建导致产氧光合作用的潜在进化途径。该项目将重点关注 12 个宏基因组，研究人员希望获得数据集中至少 8 种最丰富的黑色杆菌的基因组。将注释黑色杆菌箱并构建初步代谢途径。该项目将利用来自整个细菌域的标记基因的全长序列，特别关注产氧或缺氧光养生物的分类群，并使用标记基因来构建有根的“主干”树。宏基因组中不完整或短的序列将使用进化放置算法添加到树中。研究人员还将使用贝叶斯框架构建相应的系统发育树，并比较它们的拓扑结构。通过这样做，该项目旨在提高对含氧光合作用演化的理解，它引起了地球表面化学的最重大变化。具体来说，他们将记录黑色细菌内比之前发现的更广泛的代谢多样性，获得对其代谢进化、与蓝细菌的进化关系以及导致含氧光合作用起源的进化步骤的重要见解。这项研究将对限制含氧光合作用起源的关键进化过程产生总体影响。它将通过指出含氧光合作用进化的基因组记录可能被保存的位置，为未来的研究奠定基础。研究结果还将通过与教师合作制定科学的课程计划与中学生分享。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

A phylogenetically novel cyanobacterium most closely related to Gloeobacter

一种与Gloeobacter关系最密切的系统发育新蓝细菌

DOI：
10.1038/s41396-020-0668-5
发表时间：
2020-05
期刊：
The ISME Journal
影响因子：
0
作者：
Grettenberger, Christen L.;Sumner, Dawn Y.;Wall, Kate;Brown, C. Titus;Eisen, Jonathan A.;Mackey, Tyler J.;Hawes, Ian;Jospin, Guillaume;Jungblut, Anne D.
通讯作者：
Jungblut, Anne D.

Novel Gloeobacterales spp. from Diverse Environments across the Globe

新型胶杆菌属 (Gloeobacterales spp.)