Chronobiology: Not everything revolves around the sun

Researchers in Vienna shed light on the interplay of a worm's inner clocks For a long time, molecular chronobiology has almost exclusively focused on circadian rhythms that are driven by the changes of day and night and hence follow the daily cycle of the sun. However, especially in the sea, the cradle of evolution, organisms set their pace also according to the moon. Kristin Tessmar-Raible and her team at the Max F. Perutz Laboratories (MFPL) of the University of Vienna and the Medical University of Vienna now show that separate inner clocks, one for the day (set by the sun) and one for the month (set by the moon) exist. They also provide first insight how such inner clocks interact. Their findings are published in the recent edition of the journal "Cell Report". Reports that the time of reproduction of certain marine animals correlates with the lunar phases go back as far as ancient times. However, the mechanisms of these so-called circalunar rhythms are not understood. Even rather basic questions are still open, such as: Is the circalunar clock molecularly independent of the well-known daily (circadian) clock? How many inner clocks exist in such animals? And if there are independent clocks - would they interact? Using the marine worm Platynereis dumerilii as a model organism, the scientific team of Kristin Tessmar-Raible now describes the worm's circadian as well as its circalunar clocks and interactions between the two. Successful reproduction needs precise timing