Pre_GI: SWBIT SVG BLASTN

Query: NC_004061:31500 Buchnera aphidicola str. Sg (Schizaphis graminum), complete genome

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

General Information: This strain is the symbiont of the aphid Schizaphis graminum and contains a large circular chromosome. Aphid endosymbiont. Almost all aphids contain maternally transmitted bacteriocyte cells, which themselves contain bacteria called Buchnera. The aphids live on a restricted diet (plant sap), rich in carbohydrates, but poor in nitrogenous or other essential compounds. 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_010159:2440947 Yersinia pestis Angola, complete genome

Lineage: Yersinia pestis; Yersinia; Enterobacteriaceae; Enterobacteriales; Proteobacteria; Bacteria

General Information: This strain was isolated prior to 1985 and belongs to the antiqua biovar. It can ferment rhamnonse and melibiose which is a property usually associated with Yersinia pseudotuberculosis. Strain Angola belongs to a group of atypical Yersinia pestis strains with genotypic similarities that are intermediate between Y. pestis and Y. pseudotuberuclosis strains. Genotypic studies indicate that strain Angola is the oldest Y. pestis strain analyzed to date. It carries three plasmids that are similar to other Y. pestis plasmids but have aberrant sizes. The critical virulence factor, the V antigen, is different than that encoded by typical strains of Y. pestis and there is a deletion that affects the F1 operon. Strain Angola has been shown to be virulent by aerosol in mice.