Evolutionary and comparative genomics of leptospira
DOI:
https://doi.org/10.3395/reciis.v1i2.928Keywords:
Leptospira, genome reduction, GC content, substitution rates, host rangeAbstract
The availability of complete genome sequences has allowed the study of genic and nucleotide content changes during the evolution of pathogenic and symbiont bacterial lineages. Here we present the comparative genomics between four strains belonging to two species, Leptospira interrogans (L.interrogans Lai str. 56601 and L. interrogans Copenhageni str. Fiocruz L1-130) and L. borgpetersenii (L. borgpetersenii serovar Hardjo-bovis str. JB197 and L. borgpetersenii serovar Hardjo-bovis str. L550). Strains from the latter species have reduced their host range being restricted to a host-to-host transmission cycle while the former species could survive for long periods in fresh water. A detailed compositional and substitutional analysis of 2416 tetrads of orthologs indicates that this change in environmental condition is accompanied by changes in genomic GC content that affected the entire genome. Moreover, this analysis reveals that the interspecies divergence is surprisingly large, with a synonymous/amino acid distances ratio equal to 7.17, a ratio much larger than in other groups. We show that this increased ratio is an indication of acceleration in substitutions rates that especially affected synonymous positions and is in connection with the change in base composition already described. We hypothesize that this process specifically took place in the branch that leads to L. borgpetersenii.Downloads
Published
How to Cite
Issue
Section
License
Author’s rights: The author retains unrestricted rights over his work.
Rights to reuse: Reciis adopts the Creative Commons License, CC BY-NC non-commercial attribution according to the Policy on Open Access to Knowledge by Oswaldo Cruz Foundation. With this license, access, download, copy, print, share, reuse, and distribution of articles is allowed, provided that it is for non-commercial use and with source citation, granting proper authorship credits and reference to Reciis. In such cases, no permission is required from the authors or editors.
Rights of authors’s deposit / self-archiving: The authors are encouraged to deposit the published version, along with the link of their article in Reciis, in institutional repositories.