Circadian Systems: General Perspective
Circadian Systems: General Perspective
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昼夜节律系统：一般观点
DOI：
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
C. Pittendrigh
中科院分区：
文献类型：
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作者：
C. Pittendrigh
生命的物理环境以几个主要的周期性为特征，这些周期性来自地球和月球相对于太阳的运动。从数十亿年前的起源开始，生命就不得不科普明显的光和温度的日和年周期。当海洋边缘被入侵时，潮汐周期就对生命提出了挑战;在陆地上，湿度和其他日常周期被添加到光和温度的古老挑战中。这些物理周期性显然提出了挑战--白天沙漠和冬季高纬度地区的敌意--自然选择不得不科普这些挑战;另一方面，基于天体力学的这些周期的独特稳定性为选择提供了一个明确的机会：它们的可预测性使预期规划成为一种可行的策略。其结果是，在真核系统中，新陈代谢和行为的先天时间程序普遍存在，这些程序最适合在物理变化的外部周期的有限部分进行。夜间活动的啮齿类动物的进食行为被安排在夜间的早些时候;这种行为持续在那个阶段--在没有线索的持续黑暗中以接近24小时的间隔重复出现;肠道消化所必需的酶的动员和随后的肝脏代谢过程被适当地安排在同一时间（或稍早）。
The physical environment of life is characterized by several major periodicities that derive from the motions of the earth and the moon relative to the sun. From its origin some billions of years ago, life has had to cope with pronounced daily and annual cycles of light and temperature. Tidal cycles challenged life as soon as the edge of the sea was invaded; and on land, humidity and other daily cycles were added to the older challenges of light and temperature. These physical periodicities clearly raise challenges—caricatured by the hostility of deserts by day and of high latitudes in winter—that natural selection has had to cope with; on the other hand, the unique stability of these cycles based on celestial mechanics presents a clear opportunity for selection: their predictability makes anticipatory programming a viable strategy. The result has been widespread occurrence in eukaryotic systems of innate temporal programs for metabolism and behavior that are most appropriately undertaken during a restricted fraction of the external cycle of physical change. Feeding behavior in nocturnal rodents is programmed into early hours of the night; the behavior persists at that phase—recurring at intervals close to 24 hr—in animals retained in cueless constant darkness; and mobilization of the enzymes necessary for digestion by the intestine and subsequent metabolic processing in the liver is appropriately programmed to that same (or slightly earlier) time.