Biological clocks are found in almost all life forms, from bacteria to humans, and enable organisms to anticipate environmental cycles and regulate their behaviour and physiology accordingly. While the mechanistic principles of these endogenous timing mechanisms have been extensively studied in terrestrial model species (e. g. fruit fly or mouse), little is known in the marine environment, where life – and correspondingly, biological clocks – have evolved. Antarctic krill (Euphausia superba) is a key species endemic to the Southern Ocean, which is a high latitude region characterized by extreme seasonal fluctuations in environmental factors (photoperiod, sea ice extent, food availability). The life cycle of Antarctic krill is shaped by strong diel rhythms (DVM, metabolic activity), synchronized to the day-night cycle, and seasonal rhythms (growth, lipid accumulation, gene expression), synchronized to the seasonal change in photoperiod and food availability, making Antarctic krill highly adapted to a life under extreme conditions. Recent investigations suggest the involvement of an endogenous clock in both, diel (DVM, metabolic activity) and seasonal (e. g. growth, enzyme activity and gene expression) processes. Moreover, the molecular components of an endogenous clock have been characterized in E. superba in a transcriptomic study. However, nothing is known about the underlying mechanistic principles and the neuronal architecture of this clock and how it is synchronized to the environment, which is the key to understand diel and seasonal timing in Antarctic krill. With parts of the Southern Ocean experiencing rapid warming caused by anthropogenic driven climate change, it is of fundamental interest to understand the involvement of endogenous timing mechanisms into life cycle functions of Antarctic krill. By combining seasonal field samplings and molecular biological methods with laboratory experiments (behaviour, metabolic activity) the MEMAREs project aims to further understand the underlying principles of diel and seasonal timing in Antarctic krill to gain insights into its plasticity towards environmental change.

Participants
Prof. Dr. Charlotte Förster (University of Würzburg)
Prof. Dr. Bettina Meyer (AWI/ICBM/HIFMB)
MSc Lukas Hüppe (University of Würzburg/AWI)

Collaborators
Dr. David Wilcockson (University of Aberystwyth)
Prof. Dr. Heinrich Dircksen, University of Stockholm
Dr. Sören Häfker (University of Vienna)

Duration
2021 – 2024

Funding
DFG priority program “SPP1158 - Antarctic Research with Comparative Investigations in Arctic Ice Areas” of the German Science Foundation (DFG)