Low-coverage pyrosequencing reveals recombination and run-off replication in Bartonella henselae strains
(English)Manuscript (preprint) (Other academic)
Bartonella henselae is a natural intracellular colonizer of cats, and is transferred by blood-sucking insect vectors. It is also an opportunistic human pathogen. Two strains of B. henselae, thought to be representative of the diversity of the species, were selected for low-coverage 454 sequencing. The comparison of these two strains to the published Houston-1 reveals very high nucleotide identity and low substitution and recombination, with the remarkable exception of phages and host-interaction genes such as type IV and V secretion systems. Among the few variable genes of unknown function, BH14680, an alpha-Proteobacteria-specific gene, shows faster evolution in Bartonella compared to other alpha-Proteobacteria. Its 5’ end, which is likely coding for a domain exposed extracellularly, is under positive or very relaxed selection, and might be involved in host-interaction processes. Finally, we show that a simple genome coverage analysis reveal major genomic events such as duplications and unusual replication modes, such as the run-off replication. The latter, combined with a gene transfer agent, is thought to be a novel way to increase substitution and recombination frequencies. An extensive analysis of all bacterial pyrosequencing projects showed that it is probably Bartonella-specific.
pathogen, recombination, run-off replication, phage, gene transfer agent, pyrosequencing, evolution
Bioinformatics and Systems Biology
Research subject Evolutionary Genetics
IdentifiersURN: urn:nbn:se:uu:diva-107785OAI: oai:DiVA.org:uu-107785DiVA: diva2:232971