Sivilingeniør Ane Live Gunnes Utnes disputerer for ph.d.-graden i medisinske fag og vil offentlig forsvare avhandlingen:

Evolutionary Costs and Benefits of Natural Transformation in Acinetobacter baylyi

Kort sammendrag:

Bacteria can acquire exogenous DNA from the environment through natural transformation. Natural transformation is one mechanism of horizontal gene transfer in bacteria. Once inside the cell, the DNA can potentially be integrated into the host genome by homologous recombination. Although the impact of natural transformation on bacterial adaptation/evolution is well known, the immediate benefit for the transformable bacterium is not clear. Since there are both metabolic and genetic costs associated with taking up DNA, it is assumed that there must be a benefit in order for the trait to be maintained over evolutionary time. We have tested different hypotheses for the maintenance of natural transformation in the bacterium Acinetobacter balylyi. Through experimental evolution experiments with A. baylyi in a novel stressful environment we found that natural transformation was beneficial since it led to increased adaptation, but that this benefit was growth phase specific. Further we found that natural transformation could provide an immediate fitness benefit that was uncoupled from recombination of DNA into the genome. Last, we tested the hypothesis that natural transformation can alleviate clonal interference between beneficial mutations. (Avhandlingen er tilgjengelig for utlån hos Seksjon for forskningstjeneste, Det Helsevitenskapelige fakultet  frem til disputasdato)

Prøveforelesning over oppgitt emne holdes 29. mai, kl. 10.15, samme sted: “Characteristics and examples of antibiotic resistance spread by transformation as opposed to other means of HGT”.