Circadian ClocksCircadian RhythmBiological ClocksPeriod Circadian ProteinsCryptochromesCLOCK ProteinsPhotoperiodARNTL Transcription FactorsLightCircadian Rhythm Signaling Peptides and ProteinsSuprachiasmatic NucleusFeedback, PhysiologicalDrosophila ProteinsTranscription FactorsGene Expression RegulationNuclear Receptor Subfamily 1, Group D, Member 1FlavoproteinsDarknessChronobiology DisordersArabidopsisArabidopsis ProteinsGene Expression Regulation, PlantCasein Kinase IepsilonPhotoreceptor Cells, InvertebrateBasic Helix-Loop-Helix Transcription FactorsSynechococcusNeurospora crassaActivity CyclesNuclear ProteinsLight Signal TransductionMelatoninMotor ActivityE-Box ElementsPineal GlandCasein Kinase IdeltaMutationJet Lag SyndromeDrug ChronotherapyModels, BiologicalOscillometryCell Cycle ProteinsMammalsPeriodicityNeurosporaTrans-ActivatorsFlowersDrosophilaArylalkylamine N-AcetyltransferaseHypocotylDrosophila melanogasterGenes, PlantDiapause, InsectRNA, MessengerEye ProteinsPhytochromeTranscription, GeneticLuciferasesCyanobacteriaTemperaturePhotobiologyAnimals, Genetically Modified