Circadian rhythms are daily changes in metabolism, physiology and behaviour of all living organisms. These rhythms are generated by an endogenous and resettable oscillator known as the “circadian clock”. The clock synchronizes various biological processes with day and night and allows cells or organisms to perform tasks at biologically advantageous times during the day-night cycle. The eukaryotic clock that orchestrates the rhythms is organized as a conserved transcription-translation feedback loop (TTFL) system. The rhythmic daily change in transcript abundance is characteristic of the clock mechanism, as is the rhythmic change in protein that follows the changes in mRNA. At a molecular level, different cellular times are defined by particular combinations of the amounts of clock gene mRNA and protein. Our recent results show that Lingulodinium polyedrum circadian system does not require rhythmic RNA and thus uses a mechanism for determining cellular time that is distinct from the conserved eukaryotic TTFL. This makes it an ideal model to study alternative mechanisms for the generation of circadian time. Furthermore, to address the key issues relating to the evolution of the circadian clocks I plan to compare Lingulodinium system with other algae models.

The functional unit for generation of circadian rhythms are single cells. Due to the strong association of cellular metabolism with the clock its disruption leads to many metabolic disorders and diseases such as cancer, diabetes, obesity, sleep problem etc. Therefore, understanding how the clock regulates cellular physiology is critical and manipulating them can have wide range of applications, from increasing production of commercially important bioactive molecules (drugs, biofuels etc.) in microalgae to finding cure for circadian rhythm disorders.