title: Effects of continuous white light and 12h white-12h blue light-cycles on the expression of clock genes in diencephalon, liver, and skeletal muscle in chicks.
abstract: The core circadian clock mechanism relies on a feedback loop comprised of clock genes, such as the brain and muscle Arnt-like 1 (Bmal1), chriptochrome 1 (Cry1), and period 3 (Per3). Exposure to the light-dark cycle synchronizes the master circadian clock in the brain, and which then synchronizes circadian clocks in peripheral tissues. Birds have long been used as a model for the investigation of circadian rhythm in human neurobiology. In the present study, we examined the effects of continuous light and the combination of white and blue light on the expression of clock genes (Bmal1, Cry1, and Per3) in the central and peripheral tissues in chicks. Seventy two day-old male chicks were weighed, allocated to three groups and maintained under three light schedules: 12h white light-12h dark-cycles group (control); 24h white light group (WW group); 12h white light-12h blue light-cycles group (WB group). The mRNA levels of clock genes in the diencephalon were significantly different between the control and WW groups. On the other hand, the alteration in the mRNA levels of clock genes was similar between the control and WB groups. Similar phenomena were observed in the liver and skeletal muscle (biceps femoris). These results suggest that 12h white-12h blue light-cycles did not disrupt the circadian rhythm of clock gene expression in chicks.
authors.affiliation: Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan. Electronic address: honda@tiger.kobe-u.ac.jp.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Honda
authors.affiliation: Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kondo
authors.affiliation: Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan.
authors.forename: Daichi
authors.initials: D
authors.lastname: Hiramoto
authors.affiliation: Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan.
authors.forename: Takaoki
authors.initials: T
authors.lastname: Saneyasu
authors.affiliation: Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamisoyama
mesh_terms: D000818:Animals; D002645:Chickens; D057906:Circadian Clocks / Q000235:genetics*; D002940:Circadian Rhythm / Q000235:genetics*; D004027:Diencephalon / Q000528:radiation effects; D005786:Gene Expression Regulation / Q000528:radiation effects; D008027:Light; D008099:Liver / Q000528:radiation effects; D018482:Muscle, Skeletal / Q000528:radiation effects; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D012333:RNA, Messenger
keywords: Blue lighting; Chicken; Clock; Light; White lighting