umu.sePublications
Change search
ReferencesLink to record
Permanent link

Direct link
Minor fitness costs in an experimental model of horizontal gene transfer in bacteria.
Show others and affiliations
2014 (English)In: Molecular biology and evolution, ISSN 0737-4038, E-ISSN 1537-1719, Vol. 31, no 5Article in journal (Refereed) Published
Abstract [en]

Genes introduced by horizontal gene transfer (HGT) from other species constitute a significant portion of many bacterial genomes, and the evolutionary dynamics of HGTs are important for understanding the spread of antibiotic resistance and the emergence of new pathogenic strains of bacteria. The fitness effects of the transferred genes largely determine the fixation rates and the amount of neutral diversity of newly acquired genes in bacterial populations. Comparative analysis of bacterial genomes provides insight into what genes are commonly transferred, but direct experimental tests of the fitness constraints on HGT are scarce. Here, we address this paucity of experimental studies by introducing 98 random DNA fragments varying in size from 0.45 to 5 kb from Bacteroides, Proteus, and human intestinal phage into a defined position in the Salmonella chromosome and measuring the effects on fitness. Using highly sensitive competition assays, we found that eight inserts were deleterious with selection coefficients (s) ranging from ≈ -0.007 to -0.02 and 90 did not have significant fitness effects. When inducing transcription from a PBAD promoter located at one end of the insert, 16 transfers were deleterious and 82 were not significantly different from the control. In conclusion, a major fraction of the inserts had minor effects on fitness implying that extra DNA transferred by HGT, even though it does not confer an immediate selective advantage, could be maintained at selection-transfer balance and serve as raw material for the evolution of novel beneficial functions.

Place, publisher, year, edition, pages
2014. Vol. 31, no 5
National Category
Microbiology Evolutionary Biology
Identifiers
URN: urn:nbn:se:umu:diva-118569DOI: 10.1093/molbev/msu076PubMedID: 24536043OAI: oai:DiVA.org:umu-118569DiVA: diva2:915965
Available from: 2016-03-31 Created: 2016-03-23 Last updated: 2016-03-31

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed
In the same journal
Molecular biology and evolution
MicrobiologyEvolutionary Biology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 7 hits
ReferencesLink to record
Permanent link

Direct link