IMAGINE: Adaptation of cyanobacterial light harvesting and metal homeostasis traits to environmental change.

蓝藻是水生食物网基础上的光合微生物。它们生活在不同类型的环境中，从原始的海水到高营养，有时是金属污染的海湾。研究人员发现，一种蓝藻物种已经从海洋环境过渡到圣地亚哥湾，这将需要它适应不同的条件，如光质量和受污染的水域。他们将检查这种蓝藻中的特定基因是否会对新环境做出反应而发生变化，或者蓝藻是否会从环境中的DNA中获取新的基因，以帮助它适应圣地亚哥湾的环境。由于地球环境正在迅速变化，了解像蓝藻这样的生物如何响应变化的机制以及它们适应能力的限制是很重要的。这项研究的主要目标是确定蓝藻如何能够适应不同的环境。此外，该项目还将培养分子生态学技术方面的博士后和本科生。pi还提议与丘拉维斯塔南圣地亚哥湾的Living Coast探索中心合作，开展一个以微生物学为重点的野生动物日营项目。露营者将会发现圣地亚哥湾是如何充满了浮游生物、微生物和其他小物种的世界，并依赖于它们。这个项目的独特之处在于，学生们将有机会参与海湾的采样，并使用显微镜观察光合微生物。水生微生物可以适应和多样化，以占据新的生态位。对于蓝藻来说，光捕获和金属稳态的复杂特性是适应光质量（颜色）或微量金属数量差异的新环境的特征的例子。环境序列数据显示，一种通常是少营养的海洋蓝藻“物种”，聚球菌进化枝II，已经越过了海岸带（由其他进化枝主导），并适应了富营养化圣地亚哥湾内部的条件。这一现象是一个理想的案例研究，了解微生物如何适应复杂性状发生在分子水平上。利用流式分选细胞的分离株和单细胞基因组，研究人员将确定阳性选择是否对聚球菌基因组中的特定基因起作用。此外，聚囊球菌II菌株也可能通过水平基因转移在圣地亚哥湾获得新的基因。基因敲除/敲入将用于测试特定基因的功能优势。PIs提议与位于圣地亚哥湾的Living Coast Discovery Center合作开发一个以微生物学为重点的野生动物日营项目。露营者将发现圣地亚哥湾是如何充满微生物，并依赖微生物生存的。这个项目的独特之处在于，学生将有机会与科学家见面，参观工作实验室，参与海湾采样，并利用光学和荧光显微镜观察微生物。该项目还将在分子生态学和进化技术方面培养一名博士后和本科生。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Cyanobacteria are photosynthetic microorganisms at the base of aquatic food webs. They occupy different types of environments from pristine ocean waters to high nutrient, sometimes metal-polluted bays. The investigators have found that one cyanobacterial species has transitioned from a marine environment into the San Diego Bay, which would require it to adapt to different conditions such as light quality and polluted waters. They will examine if specific genes in this cyanobacterium changed in response to the new environment or if the cyanobacterium picked up new genes from DNA in its environment to help it adapt to the San Diego Bay environment. Since the earth’s environment is changing rapidly, it is important to understand the mechanisms of how organisms such as cyanobacteria will change in response, and what might be the limits on their ability to adapt. The main goal of this research is to determine how cyanobacteria are able to adapt to different environments. In addition, the project will train a post-doctoral fellow and undergraduates in techniques in molecular ecology. The PIs also propose to develop, in collaboration with the Living Coast Discovery Center in south San Diego Bay in Chula Vista, a program for a Wildlife Day Camp focused on microbiology. Campers will discover how the San Diego Bay is filled with, and dependent on, the world of plankton, microbes, and other small species. This program will be unique in that students will have an opportunity to participate in sampling on the Bay and use microscopes to view photosynthetic microbes.Aquatic microbes can adapt and diversify to occupy new ecological niches. For cyanobacteria, the complex traits of light-harvesting and metal homeostasis are examples of traits that adapt to new environments with differences in light quality (color) or amounts of trace metals. Environmental sequence data show that a normally oligotrophic “species” of marine cyanobacteria, the Synechococcus clade II, has crossed over the coastal zone (dominated by other clades) and adapted to the conditions inside eutrophic San Diego Bay. This phenomenon is an ideal case study for understanding how microbial adaptation of complex traits occurs at the molecular level. Using isolates and single cell genomes of flow-sorted cells, the investigators will determine if positive selection has been operating on specific genes in the Synechococcus genome. In addition, Synechococcus clade II strains may also be acquiring novel genes in San Diego Bay through horizontal gene transfer. Gene knockouts/knockins will be used to test the functional advantage of specific genes. The PIs propose to develop, in collaboration with the Living Coast Discovery Center, located on San Diego Bay, a program for a Wildlife Day Camp focused on microbiology. Campers will discover how the San Diego Bay is filled with, and dependent on, microbes. This program will be unique in that students will have an opportunity to meet scientists, visit working labs, participate in sampling on the Bay and utilize light and epifluorescence microscopes to view microbes. The project will also train a post-doctoral fellow and undergraduates in techniques in molecular ecology and evolution.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.