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.
