Dissecting the mechanistic basis of moon-controlled monthly timing mechanisms in marine environments

ended

The correct timing of biological processes is crucial for organisms. The moon is an important timing cue for numerous marine species, ranging from brown and green algae to corals, worms and fishes. It acts either directly or via the synchronization of monthly (circalunar) inner clocks. Such lunar timing mechanisms typically control the gonadal maturation and behavioral changes associated with reproductive rhythms, including spectacular mass-spawning events. Despite their biological importance, the mechanisms underlying circalunar clocks, as well as their responses to naturalistic stimuli are unknown. My lab has spearheaded research into the mechanisms underlying circalunar timing systems, establishing tools and resources for two well-suited, complementary animal models: Platynereis dumerilii and Clunio marinus. We unraveled first principles of the circalunar clock, e.g. its continuous function in the absence of oscillation of the daily (circadian) clock. Recent unpublished work revealed the first gene that functionally impacts on circalunar rhythms. By capitalizing on these powerful tools and key findings, my lab is in a leading position to dissect the mechanisms of circalunar clocks and their interaction with other rhythms and the environment via three objectives: (1) A reverse genetic approach to unravel how nocturnal light sets the phase of the monthly clock. (2) A forward genetic screen to identify molecules involved in the circalunar clock, an experimental strategy that was the key to unravel the principles of animal circadian clocks. (3) By growing animals in outside tanks and subjecting them to established analyses, we will test our lab-based results in more naturalistic conditions. This project will substantially deepen our mechanistic insight into marine rhythms – ecologically important phenomena – and provide a first basis to predict how environmental changes might impact on timing systems of crucial importance to many marine species and likely beyond.