Experimental approaches for a better understanding of new gene evolution

This application describes three four-year projects where we use the powerful combination of bacterial genetics and experimental evolution to study the mechanisms that underlie evolution, with the main focus on the evolution of new genes.As model system we use two genes that have the capacity to evolve new functions.

Both the original and the new functions of both genes confer selectable phenotypes (growth on minimal medium or antibiotic resistance), making selection and detection simple, sensitive and quantifiable.Some of the questions that will be studied include:How can generalist enzymes evolve from specialist ancestors, even in the face of strong trade-offs where mutations that generate or improve the new function almost always lead to loss of the original function?Why do the same enzymes from different organisms differ in their capacities to evolve new functions?What is the effect of horizontal gene transfer (HGT) on the evolution of new genes?

Does new functions evolve faster in populations where HGT occurs compared to in purely clonal populations?These studies will lead to new knowledge of the processes involved in evolution of new genetic functions and phenotypic innovations.

In addition to advancing basic science in the field of evolutionary biology, the results will have implications for industrial or environmental applications and for medically relevant problems such as better understanding of the evolution of antibiotic resistance.