PhD Scholarship Physiology of Circadian Rhythms at The University of Queensland

The liver plays an essential role in many aspects of animal physiology. It has an important function in lipid, carbohydrate, and xenobiotic metabolism. Furthermore, the liver is also a secretory organ that synthesizes bile acids and most of the proteins of the blood, such as albumin, coagulation factors, and complement proteins involved in the immune response. All of these functions do not occur at the same time. Instead, rhythmic liver metabolism is regulated by the circadian clock, an evolutionarily acquired gene network that synchronizes physiology to the environmental changes caused by succession of day and night.

As a consequence of the crucial role of circadian rhythms in physiology, their disruption leads to numerous metabolic and neurological pathologies. There is an increasing incidence of metabolic disorders caused by disrupted circadian rhythms, for example due to increasing shift work and other changing sleep and feeding patterns. There is a therefore a pressing need to better understand the physiological mechanisms that underpin such rhythmic metabolic changes, and the consequences of their disturbance.

Our research has shown that in mice the liver can be up to 30% larger during the night when these animals are active, than during the day. However, this phenomenon occurs only when feeding rhythm is synchronized with the active phase. This observation suggests that a signal occurring during the day opposes the effect of feeding. Nevertheless, the factors contributing to daily liver size fluctuation are still poorly understood. The goal of this project is the characterization of the molecular mechanisms involved in the regulation of rhythmic liver size, in particular through the regulation of protein secretion, and its impact on animal metabolism.

To be eligible to apply, you must also meet the entry requirements for Higher Degrees by Research at UQ. Please visit theGraduate School’s website.