Kronobiologi
David Hazlerigg
Professor in Arctic Chronobiology and Physiology
Unit: Department of Arctic and Marine Biology
Circannual rhythms, Photoperiodism, Neuroendocrinology, Developmental programming, Comparative physiology.
Even Jørgensen
Professor
Unit: Department of Arctic and Marine Biology
Min forskningsinteresse knytter seg til de fasinerende tilpasninger som er utviklet hos fisk som lever i et barskt og skiftende miljø ved høye breddegrader. Den anadrome (sjøvandrende) livsstrategien til røye (Salvelinus alpinus) er en dominerende og høyt skattet forskningsmodell. Denne modellen brukes til å fremskaffe kunnskap om hvordan hjernen regulerer appetitt og energibalanse i en art som gjennom året veksler mellom langtids fravær av appetitt (anoreksi) gjennom vinteren i ferskvann og intens spiseaktivitet gjennom det korte sjøvannsoppholdet om sommeren. Videre er det et fokus på hvordan hormonelle akser som regulerer smoltifisering (forberedelse til opphold i sjøen) og stress integrerer med de mekanismene som regulerer appetitt, siden disse mekanismene sammenfaller i tid. Sist, men ikke minst, er det viktig å skaffe tilveie kunnskap om hvordan sesongmessige prosesser som for eksempel smoltifisering “times” til den riktige tid på året. Studier gjennomføres både i felt og under kontrollerte betingelser i lab. Selv om mye av denne forskningen kan betegnes som grunnforskning, er det også klart at resultatene vil ha betydning både for fremtidig forvaltning av nordlige fiskebestander og for oppdrett av slike arter.
Shona Wood
Associate professor in Arctic chronobiology and physiology
Unit: Department of Arctic and Marine Biology
Accurate timing and anticipation of seasonal changes is required to initiate physiological adaptations over the course of the year such as hibernation, changes in metabolism, fattening and reproductive activity. To achieve this, organisms have evolved complex seasonal timekeeping systems that rely on day length sensing (photoperiodism), coupled to innate long-term timers ("circannual clock"). The fundamental biological processes giving rise circannual rhythms are not known for any organism. This is a highly integrative topic of wide relevance, integrating multiple levels of understanding from genome to ecosystem. Within this area, my specific interests are:
- The cellular and molecular mechanisms involved in seasonal timekeeping processes
- The adjustment of homeostatic set points in physiology (rheostasis)
- The function of a specialised cell type in the hypothalamus, the tanycyte, in the above processes
- The use of hibernation and maternal photoperiodic programming to investigate the above processes
Current projects:
- Arctic seasonal timekeeping initiative (ASTI), role: Deputy director
ASTI is a capacity-building project to establish UiT as a centre of excellence for research into seasonal timekeeping mechanisms. This fills a strategic gap in chronobiology research worldwide, and is an excellent fit to UiT as the world’s northernmost research university. See the website for themes and specific research projects.
- Tromsø Forskningsstiftelse (TFS) starter grant: Epigenetic light, role: project leader
Website. The project aim was establish my lab in seasonal timekeeping and hibernation at the University of Tromsø. Specific areas of research were the epigenetic basis of seasonal timing, the role of circadian clocks in seasonal timekeeping, and maternal photoperiodic programming effects.
- Sentinel North Transdisciplinary Research Program Université Laval and UiT, The role of circadian clocks in seasonal synchrony in the Arctic, role: Co-PI
This is a comparative circadian/seasonal clockwork project with an emphasis on birds, fish and diatoms.
- Clocks and hypoxia: Linking oxygen to time, role: Co-PI
This is a project investigates the role of circadian clocks and hypoxia in a
diving mammal (hooded seal). It uses high-resolution respirometry of mitochondria, astrocyte/neuronal culture techniques, and lentiviral
reporters to unpick responses to hypoxia in a highly hypoxia-tolerant
animal.