Functional and molecular characterization of the circadian clock in the Antarctic key species Euphausia superba

The Antarctic krill (Euphausia superba) is a key species of the Southern Ocean ecosystem that plays a central role in the Antarctic food web. Available evidence indicates that krill is equipped with an endogenous timing system, which enables it to synchronize its metabolism and behaviour with an environment characterized by extreme seasonal changes in terms of day length, food availability, and surface ice extent. Recently, the first transcriptional and translational feedback loop of the krill circadian clock has been defined, showing both mammalian and insect features that presumably contribute to evolutionary strategies to cope with the challenges of polar environment. We plan to complete our knowledge of the molecular architecture of the krill circadian clock by functionally characterizing the second transcriptional and translational feedback loop and identifying photolyases that are involved in repairing UV-induced DNA damage and their connection with the circadian clock. Since several studies have demonstrated that miRNAs are involved in post-transcriptional regulation of fly clock or clock-controlled genes, we would also like to identify pre-miRNAs and mature miRNAs involved in regulation of the circadian clock machinery in E. superba. Once the molecular architecture of krill clock machinery has been elucidated, we aim at studying the mechanisms through which the endogenous timing system synchronises daily and seasonal behavioural patterns and physiological functions by analysing the expression profiles of clock and clock-controlled genes in krill sampled in different seasons under different photoperiodic regimes of the Southern Ocean. The main objectives of our project are: 1) to define the molecular architecture and functioning of the krill circadian clock; 2) to identify photolyases and to define their connection with the krill circadian clock; 3) to investigate the role of miRNAs in post-transcriptional modulation of the circadian clock genes in kril