Circadian clock in Ciona intestinalis revealed by microarray analysis and oxygen consumption
Circadian clock in Ciona intestinalis revealed by microarray analysis and oxygen consumption
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DOI：
10.1093/jb/mvp160
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发表时间：
2010-02-01
影响因子：
2.7
通讯作者：
Ishida, Norio
中科院分区：
文献类型：
--
作者：
Minamoto, Toshifumi;Hanai, Shuji;Ishida, Norio
最近揭示了使大多数动物适应环境周期的内源性生物钟的分子机制。海鞘的基因组草案已经被描述，海鞘是一种接近脊椎动物的模型动物。然而，肠棒状杆菌基因组缺乏脊椎动物和昆虫共有的经典时钟基因，例如 Per、Bmal 和 Clock。在这里，我们在生理和分子水平上发现了昼夜节律。一天中，光阶段的耗氧率较低，黑暗阶段的耗氧率较高，并且节律在持续黑暗的情况下高度减弱并持续。从微阵列分析中，提取了 396 个点（占总数的 1.8%；对应于 388 个克隆）作为昼夜节律表达的候选者。我们通过RNA印迹证实了几个候选基因的昼夜节律表达。此外，四个节律性表达基因中的三个显示出相移至延长的光周期。然而，大多数已知的时钟基因并没有振荡。这些数据表明，肠杆菌具有独特的分子生物钟，与脊椎动物和昆虫相比，日常环境变化对海鞘进化的影响并不那么强烈。
The molecular mechanisms of the endogenous circadian clocks that allow most animals to adapt to environmental cycles have recently been uncovered. The draft genome of the ascidian, Ciona intestinalis, a model animal that is close to vertebrates, has been described. However, the C. intestinalis genome lacks the canonical clock genes such as Per, Bmal and Clock that are shared by vertebrates and insects. Here, we found the circadian rhythms at the physiological and molecular levels. The oxygen consumption rate was lower during the light phase and higher during the dark phase during a day, and the rhythm highly damped and continued under constant darkness. From the microarray analysis, the 396 spots (1.8% of the total; corresponding to 388 clones) were extracted as candidates for circadian expression. We confirmed the circadian expression of several candidate genes by northern blotting. Furthermore, three of four rhythmic expressed genes showed phase-shifts to prolonged light period. However, most of known clock genes did not oscillate. These data suggest that C. intestinalis have a unique molecular circadian clock and the daily environmental change is not such a strong effect for sea squirt in its evolution when compared to vertebrates and insects.