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Evolutionary dynamics of full genome content in Escherichia coli
Author(s) -
Ochman Howard,
Jones Isaac B.
Publication year - 2000
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/19.24.6637
Subject(s) - orfs , evolutionary ecology , biology , genome , ecology , evolutionary biology , genetics , gene , open reading frame , host (biology) , peptide sequence
The evolutionary history of the entire Escherichia coli chromosome was traced by examining the distribution of the ∼4300 open reading frames (ORFs) from E.coli MG1655 among strains of known genealogical relationships. Using this framework to deduce the incidence of gene transfer and gene loss, a total of 67 events—37 additions and 30 deletions—were required to account for the distribution of all genes now present in the MG1655 chromosome. Nearly 90% of the ORFs were common to all strains examined, but, given the variation in gene content and chromosome size, strains can contain well over a megabase of unique DNA, conferring traits that distinguish them from other members of the species. Moreover, strains vary widely in their frequencies of deletions, which probably accounts for the variation in genome size within the species.