Transposable elements as a source of environmentally dependent phenotypic variation

Transposable elements as a source of environmentally dependent phenotypic variation
Genomes are riddled with parasitic DNA, some of which is mobile and can jump from one location to another. These “jumping genes”, or transposable elements, use this tactic to spread selfishly through genomes. As they make up large fractions of the DNA carried by most eukaryotic species, including roughly half of our own human genome, this selfish strategy is clearly hugely evolutionarily successful. In recent years, it has also become clear that selfish DNA can also sometimes be beneficial. Several stunning examples of rapid adaptation—the textbook example of industrial melanism in the peppered moth foremost amongst them—have turned out to be caused by transposable element insertions, showing that they can be a source of adaptive genetic variation.

The aim of this PhD project is to understand how transposable elements give rise to phenotypic variation by affecting the regulation of genes — What kinds of effects do transposable elements have on gene expression? Do these effects depend on the environment? And do they give rise to potentially adaptive genetic variation? We will address these questions using Drosophila fruit flies as a model system, allowing us to take advantage of their extremely well-characterized genome, and fly lines that differ only in their transposable element content.

The ideal student will have a keen interest in evolutionary genetics, and will be trained in molecular techniques for measuring gene expression, fly work, and data analysis. They will benefit from a strong supervisory team at Liverpool, including Andrea Betancourt (who studies Drosophila transposable element evolution), Ilik Saccheri (an ecological geneticist with an interest in transposable elements), Seth Barribeau (who studies insect gene expression), and from an additional supervisor in Sheffield, Lisa Smith (a transposable element biologist working in plant systems).