2005 Annual Science Report
University of California, Los Angeles Reporting | JUL 2004 – JUN 2005
Genomic Approach to Understanding of the Evolution of Sulfur Metabolisms
Sorel Fitz-Gibbon and collaborators (listed below) have entered into an agreement with the DOE’s Joint Genome Institute to sequence five genomes of the genus Pyrobaculum and close relatives. These closely related organisms are extraordinarily diverse in their metabolic repertoire, including many sulfur-based metabolisms, making them an ideal group for the study of the mechanisms and evolution of basic energy metabolisms. Additionally, it will be of great interest to see if the unexpected clustering of large numbers of sulfur metabolism genes seen in P. aerophilum is also seen in the other Pyrobaculum genes. This information will be important for studies of function and regulation and may also be important for directing future studies of environmental samples. Caldivirga maquilingensis is the outgroup genome of the group and is particularly important for studies of sulfur metabolisms as it is the only Crenarchaeota clearly reported to use sulfate reduction for energy gain. Analysis of the sulfate reduction genes of this organism may lend further support to the idea that sulfate reduction arose early in the Archaeal lineage, making it more likely that microbial sulfate reduction was an important component of ancient Earth%'s geochemical cycles.
Sorel Fitz-Gibbon and Christopher House (Penn State Astrobiology) continued their collaboration on whole genome comparisons and hierarchical classifications. They are preparing a new publication on a novel classification scheme based on measurements of conserved gene order. This broad analysis will additionally report on correlations of nucleotide level versus gene order evolutionary changes across different lineages.
Sorel Fitz-Gibbon has made progress in the initial steps towards developing a genetic system for Pyrobaculum. Focusing on Pyrobaculum calidifontis she is currently working on plating conditions and growth in minimally supplemented basal salt media.