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

在各种生理和行为参数中观察到的昼夜节律，对于生活在地球上的生物体适应自然环境是重要的。最近，我们成功地克隆了构成日本鹌鹑生物钟核心的鸟类时钟基因(qper2、qper3、qClock)。在本项目中，我们利用这些时钟基因分析了鸟类的生物钟和光周期时间测量。研究结果总结如下。(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均有表达。特别是，qPer2和qPer3表现出不同的昼夜节律(Mol Brain Res，2000)。(2)鸟类SCN的鉴定：利用Clock基因的表达鉴定了已有20多年未确定其位置的鸟类SCN(Am J Physiol，2001)。(3)褪黑素对家禽SCN中Clock基因表达的影响：因为褪黑素参与了…的调节观察了更多的鸟类昼夜节律，褪黑素对SCN时钟基因表达的影响。结果表明，褪黑素不影响时钟基因的转录，但褪黑素似乎影响SCN细胞之间的偶联(Europ J Neurosci，2002)，(4)时钟基因和光周期反应：为了研究时钟基因是如何参与光周期时间测量的，我们研究了长日照和短日照条件下，时钟基因在松果体、SCN和漏斗核中的表达模式。结果表明，这种模式在SCN和松果体中改变，但在作为光周期反应中心的漏斗核中变化不大。(5)时钟基因在卵巢中的功能：检测了时钟基因在卵巢中的表达，结果表明卵巢中的时钟对排卵有调节作用。(6)Clock基因的个体发育：以鸡胚为材料，研究了Clock基因表达的个体发育。结果表明，由于在恒定的黑暗条件下没有观察到Clock基因的表达，所以Clock基因的表达需要一个明暗循环。(7)控制光周期反应的新基因：我们在日本鸣禽中分离到一个新的光周期反应调控基因。较少

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