Dataset Information

Defining natural species of bacteria: clear-cut genomic boundaries revealed by a turning point in nucleotide sequence divergence.

ABSTRACT:

Background

Bacteria are currently classified into arbitrary species, but whether they actually exist as discrete natural species was unclear. To reveal genomic features that may unambiguously group bacteria into discrete genetic clusters, we carried out systematic genomic comparisons among representative bacteria.

Results

We found that bacteria of Salmonella formed tight phylogenetic clusters separated by various genetic distances: whereas over 90% of the approximately four thousand shared genes had completely identical sequences among strains of the same lineage, the percentages dropped sharply to below 50% across the lineages, demonstrating the existence of clear-cut genetic boundaries by a steep turning point in nucleotide sequence divergence. Recombination assays supported the genetic boundary hypothesis, suggesting that genetic barriers had been formed between bacteria of even very closely related lineages. We found similar situations in bacteria of Yersinia and Staphylococcus.

Conclusions

Bacteria are genetically isolated into discrete clusters equivalent to natural species.

SUBMITTER: Tang L

PROVIDER: S-EPMC3751360 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature

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Publications

Defining natural species of bacteria: clear-cut genomic boundaries revealed by a turning point in nucleotide sequence divergence.

Tang Le L Li Yang Y Deng Xia X Johnston Randal N RN Liu Gui-Rong GR Liu Shu-Lin SL

BMC genomics 20130718

<h4>Background</h4>Bacteria are currently classified into arbitrary species, but whether they actually exist as discrete natural species was unclear. To reveal genomic features that may unambiguously group bacteria into discrete genetic clusters, we carried out systematic genomic comparisons among representative bacteria.<h4>Results</h4>We found that bacteria of Salmonella formed tight phylogenetic clusters separated by various genetic distances: whereas over 90% of the approximately four thousa ...[more]

PMID: 23865772

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Dataset Information

Defining natural species of bacteria: clear-cut genomic boundaries revealed by a turning point in nucleotide sequence divergence.

Background

Results

Conclusions

Publications

Defining natural species of bacteria: clear-cut genomic boundaries revealed by a turning point in nucleotide sequence divergence.

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