title: Fluorescence circadian imaging reveals a PDF-dependent transcriptional regulation of the Drosophila molecular clock.
abstract: Circadian locomotor behaviour is controlled by a pacemaker circuit composed of clock-containing neurons. To interrogate the mechanistic relationship between the molecular clockwork and network communication critical to the operation of the Drosophila circadian pacemaker circuit, we established new fluorescent circadian reporters that permit single-cell recording of transcriptional and post-transcriptional rhythms in brain explants and cultured neurons. Live-imaging experiments combined with pharmacological and genetic manipulations demonstrate that the neuropeptide pigment-dispersing factor (PDF) amplifies the molecular rhythms via time-of-day- and activity-dependent upregulation of transcription from E-box-containing clock gene promoters within key pacemaker neurons. The effect of PDF on clock gene transcription and the known role of PDF in enhancing PER/TIM stability occur via independent pathways downstream of the PDF receptor, the former through a cAMP-independent mechanism and the latter through a cAMP-PKA dependent mechanism. These results confirm and extend the mechanistic understanding of the role of PDF in controlling the synchrony of the pacemaker neurons. More broadly, our results establish the utility of the new live-imaging tools for the study of molecular-neural interactions important for the operation of the circadian pacemaker circuit.
authors.affiliation: Department of Genetics and Evolution, Sciences III, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.
authors.forename: Virginie
authors.initials: V
authors.lastname: Sabado
authors.affiliation: Department of Genetics and Evolution, Sciences III, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Vienne
authors.affiliation: Laboratory of Anthropology, Genetics and Peopling History, Department of Genetics and Evolution, University of Geneva, 12 rue Gustave-Revilliod, 1211 Geneva 4, Switzerland.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Nunes
authors.affiliation: Howard Hughes Medical Institute, National Center for Behavioral Genomics, Department of Biology, Brandeis University, 415 South Street, Waltham, Massachusetts 02451, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Rosbash
authors.affiliation: Department of Genetics and Evolution, Sciences III, University of Geneva, 30 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.|PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Nagoshi
mesh_terms: D000818:Animals; D001683:Biological Clocks / Q000235:genetics*; D015415:Biomarkers; D001921:Brain / Q000378:metabolism; D002940:Circadian Rhythm; D004330:Drosophila / Q000502:physiology*; D029721:Drosophila Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation; D023061:Gene Order; D017930:Genes, Reporter; D005822:Genetic Vectors / Q000235:genetics; D057054:Molecular Imaging; D009474:Neurons / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism*; D061848:Optical Imaging; D014158:Transcription, Genetic
chemical_list: D015415:Biomarkers; D029721:Drosophila Proteins; D009479:Neuropeptides; C113883:pdf protein, Drosophila