Molecular mechanisms regulating seasonal physiology

• Applicant: Professorin Dr. Annika Herwig
• Subject Area: Animal Physiology and Biochemistry
• Term: from 2012 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 210102946

Seasonal mammals undergo massive physiological changes over the course of a year. They precisely regulate metabolism, body weight and reproductive functions as appropriate to maintain energy balance in a variable environment. The physiological adaptations are the result of changes in gene expression in the brain that are driven by changes in day length via the hormone melatonin and that control key functions in energy balance and reproduction. Only in recent years has it been shown that thyroid hormone (T3) availability to the hypothalamus is essential for the photoperiodic response of birds and mammals, but to date little is known about the mechanisms T3 may trigger to rewire regulatory centres. The most extreme measure of seasonal mammals to maintain energy balance in times of food shortage is the expression of torpor. This precisely controlled hypometabolism and hypothermia is thought to be driven by metabolic signals that are integrated into a photoperiod background but central regulatory mechanisms are largely unknown. Our goal is to clarify the cascade of molecular mechanisms by which hypothalamic centers relay environmental and nutritional signals to the control of metabolism, body temperature and body weight in seasonal mammals. Understanding the mechanisms underlying these anticipatory long-term changes in energy balance in seasonal mammals is of great value because it offers exciting opportunities to identify novel mechanisms in the regulation of energy homeostasis and body weight.

• DFG Programme: Independent Junior Research Groups