Pre_GI: SWBIT SVG BLASTN

Query: NC_011833:31192 Buchnera aphidicola str. 5A (Acyrthosiphon pisum) chromosome,

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

General Information: This strain is found in the pea aphid, Acyrthosiphon pisum. Buchnera of A. pisum are the prime model of an obligate symbiosis. 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_008710:386376 Borrelia turicatae 91E135, complete genome

Lineage: Borrelia turicatae; Borrelia; Spirochaetaceae; Spirochaetales; Spirochaetes; Bacteria

General Information: This strain was isolated in the USA from the soft tick Ornithodoros turicatae. Borrelia turicatae is the causative agent of tick-borne relapsing fever in the southwestern USA. Ticks become infected with Borrelia while feeding on an infected mammal, usually a rodent or squirrel. Borrelia then multiplies rapidly, causing a generalized infection throughout the tick. While feeding, the tick passes the spirochete into a mammalian host through its infectious saliva. Relapsing fever is characterized by period of chills, fever, headache, and malaise, followed by an asymptomatic, followed by another episode of symptoms. The cycle of relapsing is due to changes in the surface proteins of Borrelia, which allow it to avoid detection and removal by the host immune system. This antigenic variation is the result of homologous recombination of silent proteins into an expressed locus, causing partial or complete replacement of one serotype with another. These plasmids carry genes involved in antigenic variation and pathogenicity.