PhD candidate: How do gut microbiomes regulate the behaviour of their animal hosts?

Most animals are active during specific times of the day, either diurnal or nocturnal. In addition, some species, referred to as crepuscular, are active mainly during dawn and dusk. Although it is clear that this diurnal preference is hardwired into the species’ genes, the genetic basis underlying this trait is largely unknown.
The fruit-fly Drosophila melanogaster is a major model organism for understanding the genetics of the circadian clock, a universal, evolutionary-conserved system that drives daily rhythms at the molecular, physiological and behavioural level. Under laboratory conditions, Drosophila is crepuscular, showing a bi-modal activity profile. However, recent experiments in our lab indicated that high variability among individuals exist, particularly in strains that derive from different wild populations. We have recently carried an artificial selection experiment in which we selected males that show the most extreme diurnal preference and mated them to their sisters. The response to selection was strong, and after 10 selection cycles we obtained highly diurnal (D) and nocturnal (N) strains. These strains provide us with a unique opportunity to understand the genetics of diurnal preference.
Here, we aim to test the impact of diurnal preference on gut bacterial communities, and their role in diurnal preference. Recent studies in various organisms, including humans, suggest that the microbial composition of the gut is highly dynamic and has major impact on host phenotypes. Pilot experiments carried out in our lab suggest that different diurnal preference is associated with a different microbiota composition. In the current project we propose to expand these experiments and also to test the impact of the microbiota on diurnal preference. Here, you would be expanding these experiments and explore further the interaction between diurnal preference and microbiome composition. The project brings together the expertise of the Tauber lab in chronobiology and the Ketley lab in microbial genetics, and consequently promotes collaboration and synergism in the Department. The project explores the links between the circadian clock and gut microbiomes, an area which is currently very topical and is expected to results in high-impact publications.