You are not currently logged in.
Access JSTOR through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Molecular Archaeology of the Escherichia coli Genome
Jeffrey G. Lawrence and Howard Ochman
Proceedings of the National Academy of Sciences of the United States of America
Vol. 95, No. 16 (Aug. 4, 1998), pp. 9413-9417
Published by: National Academy of Sciences
Stable URL: http://www.jstor.org/stable/45488
Page Count: 5
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
The availability of the complete sequence of Escherichia coli strain MG1655 provides the first opportunity to assess the overall impact of horizontal genetic transfer on the evolution of bacterial genomes. We found that 755 of 4,288 ORFs (547.8 kb) have been introduced into the E. coli genome in at least 234 lateral transfer events since this species diverged from the Salmonella lineage 100 million years (Myr) ago. The average age of introduced genes was 14.4 Myr, yielding a rate of transfer 16 kb/Myr/lineage since divergence. Although most of the acquired genes subsequently were deleted, the sequences that have persisted (≈ 18% of the current chromosome) have conferred properties permitting E. coli to explore otherwise unreachable ecological niches.
Proceedings of the National Academy of Sciences of the United States of America © 1998 National Academy of Sciences