NSF Postdoctoral Fellowship in Biology FY 2010

Thrash James C, Oakland CA

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship for FY 2010. The fellowship supports a research and training plan entitled "Understanding the genetic variety of the world's most dominant marine bacterium" for Cameron Thrash. The host institution for this research is the Oregon State University, and the sponsoring scientist is Stephen Giovannoni. SAR11 is the abbreviation used to describe a type of globally important bacteria constituting 25-50% of the bacterial cells in the world's oceans and is therefore expected to have significant impact on global biogeochemical cycling. Variants of SAR11 are found at specific times and places in marine environments and are referred to as ecotypes. SAR11 ecotypes have observable variation in their genetic content but it is unknown how this variation defines the observed ecotypes. The proposed research aims to understand the genetic basis for these different SAR11 ecotypes by looking at the similarities and differences between multiple genomes of different SAR11 organisms. By determining the genes of these organisms, it is possible to determine if specific genes are responsible for the phenotypic differences observed for distinct ecotypes, and if genetic recombination is occurring at different rates within an ecotype compared to between ecotypes. Knowledge of the genetic basis for these different ecotypes will lead to a better understanding of how these organisms interact both with their environment (e.g., what nutrients may be required for a given ecotype) and with each other (e.g., why one ecotype dominates others in a specific place), and thus strengthen ecological theory regarding SAR11 organisms. Broader motivation for this research is that understanding the basic ecology of marine microorganisms allows more accurate modeling of biogeochemical cycling of carbon in the world's oceans. This is of critical importance for anticipating the effects of climate change and informing policy regarding the global economy and resource allocation and use. Training objectives of this fellowship include achieving proficiency in computational biology and comparative genomics to compliment the Fellow's expertise in microbial physiology, with the ultimate goal being study of microbial contributions to marine biogeochemistry through a combined genomics and physiology approach.