CLONING OF AVIAN CLOCK GENES AND ANALYSIS OF CIRCADIAN CLOCK AND PHOTOTERIODIC TIME MEASUREMENT

昼夜节律，在各种生理和行为参数中观察到，对于生活在地球上的生物适应自然环境至关重要。最近，我们成功克隆了构成日本鹌鹑生物钟核心的鸟类时钟基因qPer2、qPer3、qClock。在这个项目中，我们分析了鸟类的生物钟和光周期时间测量这些时钟基因。结果总结如下：(1) clock基因表达分析：clock基因在松果体、视网膜和许多外周组织中表达。特别是，qPer2和qPer3表现出不同的昼夜节律（Mol Brain Res, 2000）。(2)禽SCN的鉴定：禽SCN的位置有20多年未被确定，通过时钟基因的表达进行了鉴定（Am J Physiol, 2001）。(3)褪黑素对禽类SCN生物钟基因表达的影响：由于褪黑素参与鸟类昼夜节律的调节，我们研究了褪黑素对SCN生物钟基因表达的影响。结果表明，褪黑激素不影响时钟基因的转录，但褪黑激素似乎影响了SCN细胞之间的偶联（Europ J Neurosci, 2002）。(4)时钟基因和光周期反应：为了研究时钟基因如何参与光周期时间测量，研究了长日和短日条件下松果体、SCN和鹌鹑基底核中时钟基因的表达模式。结果表明，这种模式在SCN和松果体中发生改变，但在作为光周期反应中心的基底核中没有改变。(5)生物钟基因在卵巢中的功能：检测了生物钟基因在卵巢中的表达，结果表明卵巢中的生物钟调节排卵。(6)时钟基因的个体发生：利用鸡胚，研究了时钟基因表达的个体发生。结果表明，时钟基因的表达需要光暗循环，因为在恒定的黑暗条件下没有表达。(7)控制光周期反应的新基因：我们在日本鹌鹑中分离到了一个调节光周期反应的新基因。少

Circadian rhythms, observed in a wide variety of physiological and behavioral parameters, are important for adaptation to natural environment in organisms living on the earth. Recently we have succeeded in cloning avian clock genes (qPer2, qPer3, qClock) which constitute the core of the circadian clock in Japanese quail. In this project, we have analyzed avian circadian clock and photoperiodic time measurement with these clock genes. The results are summarized as follows. (1) Analysis of clock gene expression : Clock genes are expressed in the pineal gland, the retina and many peripheral tissues. In particular, qPer2 and qPer3 show distinct circadian rhythms (Mol Brain Res, 2000). (2) Identification of the avian SCN : The avian SCN, the site of which had not been determined for more than 20 years, was identified with the expression of clock genes (Am J Physiol, 2001). (3) Effects of melatonin on the expression of clock gene in the avian SCN : Because melatonin is involved in the regula … More tion of avian circadian rhythms, effects of melatonin administration on the clock gene expression in the SCN were examined. The results indicate that melatonin does not affect the transcription of clock genes, but rather melatonin seems to affect the coupling among the SCN cells (Europ J Neurosci, 2002), (4) Clock genes and photoperiodic response : To examine how clock genes are involved in photoperiodic time measurement, the expression patterns of clock genes in the pineal, the SCN and the infundibular nucleus of quail under long and short days were examined. The results indicate that the patterns alter in the SCN and the pineal, but not in the infundibular nucleus which is the center for the photoperiodic response. (5) The function of clock genes in the ovary : Clock gene expression was examined in the ovary, and the results suggest that the clock in the ovary regulates the ovulation. (6) Ontogeny of clock genes : Using chicken embryo, ontogeny of clock gene expression was studied. The results indicate that light-dark cycles are required for the expression of clock gene because under constant darkness no expression was observed. (7) Novel gene controlling photoperiodic response : Weisolated a novel gene regulating photoperiodic response in Japanese quail. Less