Pre_GI: SWBIT SVG BLASTN

Query: NC_017259:25400 Buchnera aphidicola str. Ua (Uroleucon ambrosiae) chromosome,

Lineage: Buchnera aphidicola; Buchnera; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria

General Information: It is believed that the Buchnera provide the essential nutrients the host lacks. Besides a nutritional co-dependence, due to a co-existence of millions of years, Buchnera have lost the ability to produce cell surface components such as lipopolysaccharides. This makes for an obligate endosymbiont relationship between host and Buchnera. Buchnera are prokaryotic cells which belong to the gamma-Proteobacteria, closely related to the Enterobacteriaceae family. Phylogenetic studies using 16S rRNA indicate that the symbiotic relationship was established around 200-250 million years ago. Since Buchnera are closely related to Escherichia coli and Haemophilus influenzae, comparative genomic studies can shed light on the evolutionary mechanisms of intracellular endosymbiosis as well as the different underlying molecular basis between organisms with parasitic behavior and symbionts.

Subject: NC_010556:26567 Exiguobacterium sibiricum 255-15, complete genome

Lineage: Exiguobacterium sibiricum; Exiguobacterium; Bacillales Family XII; Bacillales; Firmicutes; Bacteria

General Information: This organism was isolated from a 2-3 million-year permafrost core in Siberia, Russia and can survive and grow rapidly at low temperatures. Analysis of long-term survival of psychrophilic organisms such as this one may aid understanding of the potential growth of organisms in astrobiology. Exiguobacterium sibiricum is a psychrotolerant organism able to grow at temperatures that range from -6 to 40 degrees C. This organism is also able to survive repeated freeze/thaw cycles which may contribute to its ability to survive in cold environments.