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dc.contributor.authorLeiby, Nicholas
dc.contributor.authorHarcombe, William R
dc.contributor.authorMarx, Christopher J
dc.date.accessioned2014-02-21T18:57:27Z
dc.date.issued2012
dc.identifier.citationLeiby, Nicholas, William R Harcombe, and Christopher J Marx. 2012. Multiple long-term, experimentally-evolved populations of escherichia coli acquire dependence upon citrate as an iron chelator for optimal growth on glucose. BMC Evolutionary Biology 12: 151.en_US
dc.identifier.issn1471-2148en_US
dc.identifier.urihttp://nrs.harvard.edu/urn-3:HUL.InstRepos:11729575
dc.description.abstractBackground: Specialization for ecological niches is a balance of evolutionary adaptation and its accompanying tradeoffs. Here we focus on the Lenski Long-Term Evolution Experiment, which has maintained cultures of Escherichia coli in the same defined seasonal environment for 50,000 generations. Over this time, much adaptation and specialization to the environment has occurred. The presence of citrate in the growth media selected one lineage to gain the novel ability to utilize citrate as a carbon source after 31,000 generations. Here we test whether other strains have specialized to rely on citrate after 50,000 generations. Results: We show that in addition to the citrate-catabolizing strain, three other lineages evolving in parallel have acquired a dependence on citrate for optimal growth on glucose. None of these strains were stimulated indirectly by the sodium present in disodium citrate, nor exhibited even partial utilization of citrate as a carbon source. Instead, all three of these citrate-stimulated populations appear to rely on it as a chelator of iron. Conclusions: The strains we examine here have evolved specialization to their environment through apparent loss of function. Our results are most consistent with the accumulation of mutations in iron transport genes that were obviated by abundant citrate. The results present another example where a subtle decision in the design of an evolution experiment led to unexpected evolutionary outcomes.en_US
dc.description.sponsorshipOrganismic and Evolutionary Biologyen_US
dc.language.isoen_USen_US
dc.publisherBioMed Centralen_US
dc.relation.isversionofdoi:10.1186/1471-2148-12-151en_US
dc.relation.hasversionhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC3496695/pdf/en_US
dash.licenseLAA
dc.subjectTradeoffsen_US
dc.subjectSpecializationen_US
dc.subjectIron-limitationen_US
dc.subjectCitrateen_US
dc.titleMultiple long-term, experimentally-evolved populations of Escherichia coli acquire dependence upon citrate as an iron chelator for optimal growth on glucoseen_US
dc.typeJournal Articleen_US
dc.description.versionVersion of Recorden_US
dc.relation.journalBMC Evolutionary Biologyen_US
dash.depositing.authorMarx, Christopher J
dc.date.available2014-02-21T18:57:27Z
dc.identifier.doi10.1186/1471-2148-12-151*
dash.contributor.affiliatedHarcombe, William R
dash.contributor.affiliatedLeiby, Nicholas
dash.contributor.affiliatedMarx, Christopher J


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