title: Diversity of zebrafish peripheral oscillators revealed by luciferase reporting.
abstract: In various multicellular organisms, circadian clocks are present not only in the central nervous system, but also in peripheral organs and tissues. In mammals peripheral oscillators are not directly responsive to light, but are entrained by the central oscillator in the suprachiasmatic nucleus. These individual oscillators are diverse in their free-running periods and phases. In contrast, cultured peripheral tissues and cell lines from zebrafish are not only rhythmic, but can also be directly entrained by light. Because of the convenience of studying rhythms in cultured cells, however, little has been known about properties of individual oscillators in intact zebrafish. Here, we show the remarkable diversity and consistency of oscillator properties in various peripheral organs and tissues from the period3-luciferase (per3-luc) transgenic zebrafish. Tissue-dependent differences were found in free-running period, phase, response to light, and temperature compensation. Furthermore, cycling amplitudes were reduced at lower temperatures in some, but not all, of the organs tested. Finally, we found that per3-luc rhythms can free run in both constant dark and constant light with remarkably similar amplitudes, phases, and periods, despite the fact that the mRNA of per2 and per1 has been shown not to oscillate in constant light.
authors.affiliation: Department of Biology and Biochemistry, University of Houston, 4800 Calhoun, Houston, TX 77204-5001, USA. kaneko@nsi.edu
authors.forename: Maki
authors.initials: M
authors.lastname: Kaneko
authors.forename: Nancy
authors.initials: N
authors.lastname: Hernandez-Borsetti
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Cahill
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001683:Biological Clocks / Q000502:physiology* / Q000528:radiation effects; D002940:Circadian Rhythm / Q000502:physiology / Q000528:radiation effects; D003624:Darkness; D017930:Genes, Reporter / Q000235:genetics*; D006321:Heart / Q000502:physiology; D008027:Light; D008156:Luciferases / Q000235:genetics / Q000378:metabolism*; D008164:Luminescent Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D009928:Organ Specificity; D056950:Period Circadian Proteins; D013154:Spleen / Q000502:physiology; D013696:Temperature; D014157:Transcription Factors / Q000378:metabolism; D015027:Zebrafish / Q000235:genetics / Q000502:physiology*; D029961:Zebrafish Proteins
chemical_list: D008164:Luminescent Proteins; D009687:Nuclear Proteins; D056950:Period Circadian Proteins; D014157:Transcription Factors; D029961:Zebrafish Proteins; C512647:per3 protein, zebrafish; D008156:Luciferases