title: Light acts directly on organs and cells in culture to set the vertebrate circadian clock.
abstract: The expression of clock genes in vertebrates is widespread and not restricted to classical clock structures. The expression of the Clock gene in zebrafish shows a strong circadian oscillation in many tissues in vivo and in culture, showing that endogenous oscillators exist in peripheral organs. A defining feature of circadian clocks is that they can be set or entrained to local time, usually by the environmental light-dark cycle. An important question is whether peripheral oscillators are entrained to local time by signals from central pacemakers such as the eyes or are themselves directly light-responsive. Here we show that the peripheral organ clocks of zebrafish are set by light-dark cycles in culture. We also show that a zebrafish-derived cell line contains a circadian oscillator, which is also directly light entrained.
authors.affiliation: Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS-INSERM-ULP, Illkirch, CU de Strasbourg, France.
authors.forename: D
authors.initials: D
authors.lastname: Whitmore
authors.forename: N S
authors.initials: NS
authors.lastname: Foulkes
authors.forename: P
authors.initials: P
authors.lastname: Sassone-Corsi
mesh_terms: D000818:Animals; D001683:Biological Clocks / Q000235:genetics / Q000528:radiation effects; D056926:CLOCK Proteins; D002460:Cell Line; D002940:Circadian Rhythm / Q000235:genetics / Q000528:radiation effects; D006321:Heart / Q000502:physiology / Q000528:radiation effects; D007668:Kidney / Q000502:physiology / Q000528:radiation effects; D008027:Light; D009924:Organ Culture Techniques; D013696:Temperature; D015534:Trans-Activators / Q000235:genetics; D015027:Zebrafish
chemical_list: D015534:Trans-Activators; D056926:CLOCK Proteins