Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 24 August 2007:
Vol. 317. no. 5841, pp. 1093 - 1096
DOI: 10.1126/science.1144876
Prev | Table of Contents | Next

Reports

Temporal Fragmentation of Speciation in Bacteria

Adam C. Retchless and Jeffrey G. Lawrence*

Because bacterial recombination involves the occasional transfer of small DNA fragments between strains, different sets of niche-specific genes may be maintained in populations that freely recombine at other loci. Therefore, genetic isolation may be established at different times for different chromosomal regions during speciation as recombination at niche-specific genes is curtailed. To test this model, we separated sequence divergence into rate and time components, revealing that different regions of the Escherichia coli and Salmonella enterica chromosomes diverged over a ~70-million-year period. Genetic isolation first occurred at regions carrying species-specific genes, indicating that physiological distinctiveness between the nascent Escherichia and Salmonella lineages was maintained for tens of millions of years before the complete genetic isolation of their chromosomes.

Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.

* To whom correspondence should be addressed. E-mail: jlawrenc{at}pitt.edu

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Biogeography of the Sulfolobus islandicus pan-genome.
M. L. Reno, N. L. Held, C. J. Fields, P. V. Burke, and R. J. Whitaker (2009)
PNAS 106, 8605-8610
   Abstract »    Full Text »    PDF »
On the origin of prokaryotic species.
W. F. Doolittle and O. Zhaxybayeva (2009)
Genome Res. 19, 744-756
   Abstract »    Full Text »    PDF »
The Bacterial Species Challenge: Making Sense of Genetic and Ecological Diversity.
C. Fraser, E. J. Alm, M. F. Polz, B. G. Spratt, and W. P. Hanage (2009)
Science 323, 741-746
   Abstract »    Full Text »    PDF »
Homologous Recombination in Agrobacterium: Potential Implications for the Genomic Species Concept in Bacteria.
D. Costechareyre, F. Bertolla, and X. Nesme (2009)
Mol. Biol. Evol. 26, 167-176
   Abstract »    Full Text »    PDF »
Efficient inference of bacterial strain trees from genome-scale multilocus data.
C. Than, R. Sugino, H. Innan, and L. Nakhleh (2008)
Bioinformatics 24, i123-i131
   Abstract »    Full Text »    PDF »
Resource Partitioning and Sympatric Differentiation Among Closely Related Bacterioplankton.
D. E. Hunt, L. A. David, D. Gevers, S. P. Preheim, E. J. Alm, and M. F. Polz (2008)
Science 320, 1081-1085
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)