Dataset Information

No effect of natural transformation on the evolution of resistance to bacteriophages in the Acinetobacter baylyi model system.

ABSTRACT: The adaptive benefits of natural transformation, the active uptake of free DNA molecules from the environment followed by incorporation of this DNA into the genome, may be the improved response to selection resulting from increased genetic variation. Drawing analogies with sexual reproduction, transformation may be particularly beneficial when selection rapidly fluctuates during coevolution with virulent parasites ('the Red Queen Hypothesis'). Here we test this hypothesis by experimentally evolving the naturally transformable and recombinogenic species Acinetobacter baylyi with a cocktail of lytic phages. No increased levels of resistance to phage were found in the wild type compared to a recombination deficient ?dprA strain after five days of evolution. When exposed to A. baylyi DNA and phage, naturally transformable cells show greater levels of phage resistance. However, increased resistance arose regardless of whether they were exposed to DNA from phage-sensitive or -resistant A. baylyi, suggesting resistance was not the result of transformation, but was related to other benefits of competence. Subsequent evolution in the absence of phages did not show that recombination could alleviate the cost of resistance. Within this study system we found no support for transformation-mediated recombination being an advantage to bacteria exposed to parasitic phages.

SUBMITTER: McLeman A

PROVIDER: S-EPMC5116665 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

No effect of natural transformation on the evolution of resistance to bacteriophages in the Acinetobacter baylyi model system.

McLeman Amy A Sierocinski Pawel P Hesse Elze E Buckling Angus A Perron Gabriel G Hülter Nils N Johnsen Pål Jarle PJ Vos Michiel M

Scientific reports 20161121

The adaptive benefits of natural transformation, the active uptake of free DNA molecules from the environment followed by incorporation of this DNA into the genome, may be the improved response to selection resulting from increased genetic variation. Drawing analogies with sexual reproduction, transformation may be particularly beneficial when selection rapidly fluctuates during coevolution with virulent parasites ('the Red Queen Hypothesis'). Here we test this hypothesis by experimentally evolv ...[more]

PMID: 27869203

Similar Datasets

Project description:BACKGROUND:Acinetobacter baylyi ADP1 is an ideal bacterial strain for high-throughput genetic analysis as the bacterium is naturally transformable. Thus, ADP1 can be used to investigate DNA mismatch repair, a mechanism for repairing mismatched bases. We used the mutS deletion mutant (XH439) and mutL deletion mutant (XH440), and constructed a mutS mutL double deletion mutant (XH441) to investigate the role of the mismatch repair system in A. baylyi. RESULTS:We determined the survival rates after UV irradiation and measured the mutation frequencies, rates and spectra of wild-type ADP1 and mutSL mutant via rifampin resistance assay (RifR assay) and experimental evolution. In addition, transformation efficiencies of genomic DNA in ADP1 and its three mutants were determined. Lastly, the relative growth rates of the wild type strain, three constructed deletion mutants, as well as the rifampin resistant mutants obtained from RifR assays, were measured. All three mutants had higher survival rates after UV irradiation than wild type, especially the double deletion mutant. Three mutants showed higher mutation frequencies than ADP1 and favored transition mutations in RifR assay. All three mutants showed increased mutation rates in the experimental evolution. However, only XH439 and XH441 had higher mutation rates than the wild type strain in RifR assay. XH441 showed higher transformation efficiency than XH438 when donor DNA harbored transition mutations. All three mutants showed higher growth rates than wild-type, and these four strains displayed higher growth rates than almost all their rpoB mutants. The growth rate results showed different amino acid mutations in rpoB resulted in different extents of reduction in the fitness of rifampin resistant mutants. However, the fitness cost brought by the same mutation did not vary with strain background. CONCLUSIONS:We demonstrated that inactivation of both mutS and mutL increased the mutation rates and frequencies in A. baylyi, which would contribute to the evolution and acquirement of rifampicin resistance. The mutS deletion is also implicated in increased mutation rates and frequencies, suggesting that MutL may be activated even in the absence of mutS. The correlation between fitness cost and rifampin resistance mutations in A. baylyi is firstly established.

Dataset Information

No effect of natural transformation on the evolution of resistance to bacteriophages in the Acinetobacter baylyi model system.

Publications

No effect of natural transformation on the evolution of resistance to bacteriophages in the Acinetobacter baylyi model system.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets