德國蜚蠊cry1及cry2基因對其睡眠模式之影響

Abstract

在動物界中，普遍存在休息與活動的循環，也就是睡眠的週期。睡眠可以定義為整體活動量的不活躍和感知反應的降低。在昆蟲，睡眠行為的呈現是簡單且保守的，在實驗中，以德國蜚蠊為對象，觀察其是否具有類似的睡眠行為，以及是否與生物時鐘有所聯結。根據結果顯示，德國蜚蠊睡眠行為有以下特徵：身體不活動的時期、特殊的身體姿勢、提高的覺醒閾值和體內衡定的調節機制，在本實驗中，以德國蜚蠊在白天表現出特殊的軀體姿勢，視為睡眠行為。為了證實睡眠行為與生物時鐘的關聯，以核醣核酸干擾術靜默兩個時鐘基因cry1與cry2，並以活動行為偵測軟體紀錄行為活動，結果顯示半數的靜默個體失去了活動節律。這樣的無節律感，也造成睡眠行為的改變，說明了生物時鐘控制了睡眠行為。

The universality of a basic rest-activity cycle in the animal kingdom is almost unquestioned, a prominent manifestation underlying this cycle being the sleep. Sleep can be defined as a behavioral syndrome of inactivity and reduced sensory responsiveness. In insects, it is likely that the fundamental behavioral features of sleep are conserved, in perhaps simpler ways. I decided in this study to focus on the rest period of Blattella germanica and whether or not it can be defined as a sleep-like state, and how sleep is linked to the circadian clock. Based on studies, a sleep-like state should be defined as having the following features: consolidated circadian periods of immobility, a species-specific posture, an increased arousal threshold and a homeostatic regulatory mechanism. Sleep was here defined using the specie-specific posture of the cockroaches and the timing of its occurrence within the day. To investigate the links between sleep and the circadian clock, silencing of two clock genes, cry1 and cry2 by RNA interference, has been performed. Locomotion data was then acquired using an automated tracker program to assess the periodicity of double strand RNA injected cockroaches. It appears from that study the the silencing of cry1 and cry2 through injection of dsCry1 and dsCry2 causes a loss of rhythmicity in half of individuals. This loss of rhythmicity also causes a loss of circadian organization of sleep patterns, indicating that the timing of sleep is linked to the circadian clock.