Transcriptional responses to seasonal, lunar and solar driven rhythms in a reef-building coral

Rhythms of various periodicities drive cyclical processes in organisms ranging from single cells to the largest mammals on earth, and on scales from cellular physiology to global migrations. Molecular mechanisms that generate circadian behaviours in model organisms are well studied but longer phase cycles and interactions between cycles with different periodicities are not well understood. Broadcast spawning corals are one of the best examples of an organism integrating inputs from multiple environmental parameters to synchronize their annual mating event. Corals utilize environmental input from seasonal temperature, lunar phase, and hour of the day to calibrate internal timers in preparation for their once a year reproductive event. We present a very deep RNA-seq experiment utilizing multiple analyses to differentiate transcriptional responses modulated by the interactions between these three environmental parameters. Clonal replicates of Acropora millepora were sampled over multiple 24-hour periods throughout a full lunar month and at two seasonal temperatures.