title: Adult circadian behavior in Drosophila requires developmental expression of cycle, but not period.
abstract: Circadian clocks have evolved as internal time keeping mechanisms that allow anticipation of daily environmental changes and organization of a daily program of physiological and behavioral rhythms. To better examine the mechanisms underlying circadian clocks in animals and to ask whether clock gene expression and function during development affected subsequent daily time keeping in the adult, we used the genetic tools available in Drosophila to conditionally manipulate the function of the CYCLE component of the positive regulator CLOCK/CYCLE (CLK/CYC) or its negative feedback inhibitor PERIOD (PER). Differential manipulation of clock function during development and in adulthood indicated that there is no developmental requirement for either a running clock mechanism or expression of per. However, conditional suppression of CLK/CYC activity either via per over-expression or cyc depletion during metamorphosis resulted in persistent arrhythmic behavior in the adult. Two distinct mechanisms were identified that may contribute to this developmental function of CLK/CYC and both involve the ventral lateral clock neurons (LN(v)s) that are crucial to circadian control of locomotor behavior: (1) selective depletion of cyc expression in the LN(v)s resulted in abnormal peptidergic small-LN(v) dorsal projections, and (2) PER expression rhythms in the adult LN(v)s appeared to be affected by developmental inhibition of CLK/CYC activity. Given the conservation of clock genes and circuits among animals, this study provides a rationale for investigating a possible similar developmental role of the homologous mammalian CLOCK/BMAL1 complex.
authors.affiliation: Department of Biology, University of Virginia, Charlottesville, VA, USA.
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Goda
authors.forename: Karolina
authors.initials: K
authors.lastname: Mirowska
authors.forename: Jake
authors.initials: J
authors.lastname: Currie
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Kim
authors.forename: Neethi Varadaraja
authors.initials: NV
authors.lastname: Rao
authors.forename: Gloribel
authors.initials: G
authors.lastname: Bonilla
authors.forename: Herman
authors.initials: H
authors.lastname: Wijnen
mesh_terms: D056930:ARNTL Transcription Factors / Q000235:genetics / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D001522:Behavior, Animal; D001683:Biological Clocks; D056926:CLOCK Proteins / Q000235:genetics / Q000378:metabolism; D002940:Circadian Rhythm / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development*; D008954:Models, Biological; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D056950:Period Circadian Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D056930:ARNTL Transcription Factors; C120526:Clk protein, Drosophila; D029721:Drosophila Proteins; C539040:PER protein, Drosophila; D056950:Period Circadian Proteins; C112805:cyc protein, Drosophila; D056926:CLOCK Proteins