The Dual-Oscillator System of Drosophila melanogaster Under Natural-Like Temperature Cycles
The Dual-Oscillator System of Drosophila melanogaster Under Natural-Like Temperature Cycles
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DOI：
10.3109/07420528.2012.668505
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发表时间：
2012-01-01
影响因子：
2.8
通讯作者：
Yoshii, Taishi
中科院分区：
文献类型：
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作者：
Bywalez, Wolfgang;Menegazzi, Pamela;Yoshii, Taishi
控制早晨和晚上活动的双振荡器系统可以在许多动物中找到。两个耦合振荡器跟踪黎明和黄昏，并灵活地调整其相位关系以适应季节变化。这也是真实的果蝇果蝇作为模型生物来了解双振荡器系统的分子和解剖基础。在本研究中，作者研究了哪些温度参数是至关重要的定时早上和晚上的活动高峰，通过应用自然的温度周期与不同的日长。研究发现，早高峰与上午气温升高相关，晚高峰与下午气温降低相关。这两个峰值并不发生在固定的绝对温度，但灵活地响应昼长和整体温度水平。特别是，晚高峰的相位明显取决于绝对温度水平：它在高温下延迟，而M峰的相位受影响较小。这表明两个振荡器具有不同的温度灵敏度。在生物钟突变体Clk（Jrk）和cyc（01）中不存在双峰活动节律，而在per（01）和tim（01）突变体中减少。而Clk（Jrk）突变体的活性仅跟随温度循环，per（01）和tim（01）突变体的活性不跟随温度循环，表明这些突变体不是完全无时钟的。该研究揭示了果蝇双振荡系统在不同光周期下未发现的新特征。（作者通讯：yoshii@cc.okayama-u.ac.jp）
Dual-oscillator systems that control morning and evening activities can be found in a wide range of animals. The two coupled oscillators track dawn and dusk and flexibly adapt their phase relationship to seasonal changes. This is also true for the fruit fly Drosophila melanogaster that serves as model organism to understand the molecular and anatomical bases of the dual-oscillator system. In the present study, the authors investigated which temperature parameters are crucial for timing morning and evening activity peaks by applying natural-like temperature cycles with different daylengths. The authors found that the morning peak synchronizes to the temperature increase in the morning and the evening peak to the temperature decrease in the afternoon. The two peaks did not occur at fixed absolute temperatures, but responded flexibly to daylength and overall temperature level. Especially, the phase of the evening peak clearly depended on the absolute temperature level: it was delayed at high temperatures, whereas the phase of the M peak was less influenced. This suggests that the two oscillators have different temperature sensitivities. The bimodal activity rhythm was absent in the circadian clock mutants Clk(Jrk) and cyc(01) and reduced in per(01) and tim(01) mutants. Whereas the activity of Clk(Jrk) mutants just followed the temperature cycles, that of per(01) and tim(01) mutants did not, suggesting that these mutants are not completely clockless. This study revealed new characteristics of the dual-oscillator system in Drosophila that were not detected under different photoperiods. (Author correspondence: yoshii@cc.okayama-u.ac.jp)