Publication Date:
2022-05-25
Description:
Author Posting. © The Authors, 2009. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences 106 (2009): 15909-15914, doi:10.1073/pnas.0902000106.
Description:
To what extent genotypic differences translate to phenotypic variation remains a poorly
understood issue of paramount importance for several cornerstone concepts of microbiology
including the species definition. Here, we take advantage of the completed genomic sequences,
expressed proteomic profiles, and physiological studies of ten closely related Shewanella
strains and species to provide quantitative insights into this issue. Our analyses revealed that,
despite extensive horizontal gene transfer within these genomes, the genotypic and phenotypic
similarities among the organisms were generally predictable from their evolutionary
relatedness. The power of the predictions depended on the degree of ecological specialization
of the organisms evaluated. Using the gradient of evolutionary relatedness formed by these
genomes, we were able to partly isolate the effect of ecology from that of evolutionary
divergence and rank the different cellular functions in terms of their rates of evolution. Our
ranking also revealed that whole-cell protein expression differences among these organisms
when grown under identical conditions were relatively larger than differences at the genome
level, suggesting that similarity in gene regulation and expression should constitute another
important parameter for (new) species description. Collectively, our results provide important
new information towards beginning a systems-level understanding of bacterial species and
genera.
Description:
The authors have
been supported by the DOE through the Shewanella Federation consortium and the Proteomics
Application project. The MSU work relevant to speciation was also supported by NSF (DEB
0516252).
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
