Circadian clock genes and photoperiodism: Comprehensive analysis of clock gene expression in the mediobasal hypothalamus, the suprachiasmatic nucleus, and the pineal gland of Japanese Quail under various light schedules.
In birds, the mediobasal hypothalamus (MBH) including the infundibular nucleus, inferior hypothalamic nucleus, and median eminence is considered to be an important center that controls the photoperiodic time measurement. Here we show expression patterns of circadian clock genes in the MBH, putative suprachiasmatic nucleus (SCN), and pineal gland, which constitute the circadian pacemaker under various light schedules. Although expression patterns of clock genes were different between long and short photoperiod in the SCN and pineal gland, the results were not consistent with those under night interruption schedule, which causes testicular growth. These results indicate that different expression patterns of the circadian clock genes in the SCN and pineal gland are not an absolute requirement for encoding and decoding of seasonal information. In contrast, expression patterns of clock genes in the MBH were stable under various light conditions, which enables animals to keep a steady-state photoinducible phase.
Yasuo
Shinobu
S
Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
Watanabe
Miwa
M
Okabayashi
Naritoshi
N
Ebihara
Shizufumi
S
Yoshimura
Takashi
T
D056930:ARNTL Transcription Factors; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D002940:Circadian Rhythm / Q000502:physiology*; D003370:Coturnix / Q000502:physiology*; D056931:Cryptochromes; D004268:DNA-Binding Proteins / Q000235:genetics; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins / Q000235:genetics; D051790:G-Box Binding Factors; D015870:Gene Expression / Q000502:physiology; D008029:Lighting; D008473:Median Eminence / Q000502:physiology*; D009687:Nuclear Proteins / Q000235:genetics; D017440:Photoperiod; D017956:Photoreceptor Cells, Invertebrate; D010870:Pineal Gland / Q000502:physiology*; D010904:Pituitary Gland, Posterior / Q000502:physiology*; D043562:Receptors, G-Protein-Coupled; D013493:Suprachiasmatic Nucleus / Q000502:physiology*; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
D056930:ARNTL Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D056931:Cryptochromes; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; D051790:G-Box Binding Factors; D009687:Nuclear Proteins; D043562:Receptors, G-Protein-Coupled; D015534:Trans-Activators; D014157:Transcription Factors; C119828:cry protein, Drosophila