Historical Contingency Causes Divergence in Adaptive Expression of the lac Operon

Simple item page
dc.citation.issue7
dc.citation.volume38
dc.contributor.authorKarkare K
dc.contributor.authorLai H-Y
dc.contributor.authorAzevedo RBR
dc.contributor.authorCooper TF
dc.contributor.editorWittkopp P
dc.coverage.spatialUnited States
dc.date.accessioned2023-12-15T01:28:05Z
dc.date.accessioned2024-07-25T06:39:21Z
dc.date.available2021-03-21
dc.date.available2023-12-15T01:28:05Z
dc.date.available2024-07-25T06:39:21Z
dc.date.issued2021-07
dc.description.abstractPopulations of Escherichia coli selected in constant and fluctuating environments containing lactose often adapt by substituting mutations in the lacI repressor that cause constitutive expression of the lac operon. These mutations occur at a high rate and provide a significant benefit. Despite this, eight of 24 populations evolved for 8,000 generations in environments containing lactose contained no detectable repressor mutations. We report here on the basis of this observation. We find that, given relevant mutation rates, repressor mutations are expected to have fixed in all evolved populations if they had maintained the same fitness effect they confer when introduced to the ancestor. In fact, reconstruction experiments demonstrate that repressor mutations have become neutral or deleterious in those populations in which they were not detectable. Populations not fixing repressor mutations nevertheless reached the same fitness as those that did fix them, indicating that they followed an alternative evolutionary path that made redundant the potential benefit of the repressor mutation, but involved unique mutations of equivalent benefit. We identify a mutation occurring in the promoter region of the uspB gene as a candidate for influencing the selective choice between these paths. Our results detail an example of historical contingency leading to divergent evolutionary outcomes.
dc.description.confidentialfalse
dc.edition.editionJuly 2021
dc.format.pagination2869-2879
dc.identifier.author-urlhttps://www.ncbi.nlm.nih.gov/pubmed/33744956
dc.identifier.citationKarkare K, Lai H-Y, Azevedo RBR, Cooper TF. (2021). Historical Contingency Causes Divergence in Adaptive Expression of the lac Operon.. Mol Biol Evol. 38. 7. (pp. 2869-2879).
dc.identifier.doi10.1093/molbev/msab077
dc.identifier.eissn1537-1719
dc.identifier.elements-typejournal-article
dc.identifier.issn0737-4038
dc.identifier.pii6179336
dc.identifier.urihttps://mro.massey.ac.nz/handle/10179/70625
dc.languageeng
dc.publisherOxford University Press on behalf of The Society for Molecular Biology and Evolution (SMBE)
dc.publisher.urihttps://academic.oup.com/mbe/article/38/7/2869/6179336
dc.relation.isPartOfMol Biol Evol
dc.rights(c) 2021 The Author/s
dc.rightsCC BY 4.0
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.subjectlac operon, experimental evolution
dc.subjectadaptation
dc.subjectepistasis
dc.subjectgene expression
dc.subjectAdaptation, Biological
dc.subjectBiological Evolution
dc.subjectEscherichia coli
dc.subjectEscherichia coli Proteins
dc.subjectGene Expression
dc.subjectGene Expression Regulation, Bacterial
dc.subjectGenetic Fitness
dc.subjectLac Operon
dc.subjectLac Repressors
dc.subjectMembrane Proteins
dc.subjectMutation
dc.titleHistorical Contingency Causes Divergence in Adaptive Expression of the lac Operon
dc.typeJournal article
pubs.elements-id441865
pubs.organisational-groupOther
Files
Original bundle
Now showing 1 - 3 of 3
Thumbnail Image
Name:
Published version
Size:
488.21 KB
Format:
Adobe Portable Document Format
Description:
Download
Thumbnail Image
Name:
Evidence 1
Size:
329.96 KB
Format:
Microsoft Excel XML
Description:
Download
Thumbnail Image
Name:
Evidence 2
Size:
329.9 KB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Journal Articles