This ambitious project addresses the role of hypothalamic tanycytes and epigenetic modification in regulating seasonal time keeping in mammals using two physiological paradigms, maternal programming and hibernation. This project brings together complementary skills in: 1) seasonal and developmental chronobiology (Valérie Simonneauxs team, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg), and 2) in circannual rhythms and epigenetic regulation (Shona Woods team, University of Tromsø, Norway; recently awarded a prestigious Tromsø Forskningsstiftelse Starting Grant). The project focuses on established rodent models for seasonal time keeping (raised in Strasbourg’s Chronobiotron UMS 3415), and it uses a unique infrastructure at UiT for epigenetics and chronobiology. The research will be performed by a talented PhD student, Vebjørn Jacobsen Mellum (UiT). The candidate will work half of his PhD in Strasbourg and half in Tromsø. This project offers an excellent mentorship/training opportunity for both Wood (an early carrer researcher) and Mellum. Academic beneficiaries of this research will encompass scientists studying fundamental features of neurobiology and tanycytes, dynamic epigenetic control mechanisms, obesity and metabolic disease research, as well as hibernation and seasonal researchers. This will also extend to scientists interested in comparative genomics and evolution and may offer important new insights. Further, identifying the complex molecular mechanisms orchestrating the entrance and exit of a torpor state could provide important contributions to the development of therapeutic strategies aiming at decreasing metabolic activity in the case of organ transplantation, recovery from stroke, cardiac arrest muscle disease and other ischemia/reperfusion insults.