Separate sets of cerebral clock neurons are responsible for light and temperature entrainment of Drosophila circadian locomotor rhythms
Separate sets of cerebral clock neurons are responsible for light and temperature entrainment of Drosophila circadian locomotor rhythms
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DOI：
10.1177/0748730407299344
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发表时间：
2007-04-01
影响因子：
3.5
通讯作者：
Tomioka, Kenji
中科院分区：
文献类型：
--
作者：
Miyasako, Yoko;Umezaki, Yujiro;Tomioka, Kenji
果蝇（Drosophila melanogaster）表现出双峰昼夜运动节律，在开灯和关灯之前达到峰值，这是由大脑中的多个时钟调节的。即使在光暗循环下，晚高峰的时间也高度依赖于温度，在较低的环境温度下开始较早，但几乎在同一时间结束。在目前的研究中，使用行为和免疫组织化学分析，作者表明，单独的时钟神经元组，无论是光或温度可调，形成一个功能系统驱动运动节奏。当光周期与相对于光周期提前6 h的温度周期相结合时，背侧神经元（DNs）和侧后神经元（LPNs）的TIMELESS表达时相发生了变化，而侧前脑神经元（LNs）基本保持其原始时相。因此，LN似乎优先是光可降解的，DN和LPN主要是温度可降解的。在腹侧LN组中缺乏神经肽PDF的pdf（01）突变果蝇中，即使在同步的光和温度循环下，晚高峰的开始也大大提前，并且在响应温度循环的6小时相移时，晚高峰的移动甚至比野生型果蝇更多，这表明腹侧LN对其他细胞的相位有很强的影响。这可能是由于果蝇的两组钟细胞对光和温度的适应性不同，以及它们之间的耦合作用，使果蝇的昼夜活动与每日的光和温度周期保持适当的相位关系。
The fruit fly Drosophila melanogaster shows a bimodal circadian locomotor rhythm with peaks at lights-on and before lights-off, which are regulated by multiple clocks in the brain. Even under light-dark cycles, the timing of the evening peak is highly dependent on temperature, starting earlier under lower ambient temperature but terminating almost at the same time. In the present study, using behavioral and immunohistochemical assays, the authors show that separate groups of clock neurons, either light-entrainable or temperature-entrainable, form a functional system driving the locomotor rhythm. When subjected to a light cycle combined with a temperature cycle advanced by 6 h relative to the light cycle, the dorsally located neurons (DNs) and lateral posterior neurons (LPNs) shifted their phase of TIMELESS expression, but the laterally located protocerebral neurons (LNs) basically maintained their original phase. Thus, the LNs seem to be preferentially light-entrainable and the DNs and LPNs to be primarily temperature-entrainable. In pdf(01) mutant flies that lack the neuropeptide PDF in the ventral groups of LNs, the onset of the evening peak was greatly advanced even under synchronized light and temperature cycles and was shifted even more than in wild-type flies in response to a 6-h phase shift of the temperature cycle, suggesting that ventral LNs have a strong impact on the phase of the other cells. It seems likely that the 2 sets of clock cells with different entrainability to light and temperature, and the coupling between them, enable Drosophila to keep a proper phase relationship of circadian activity with respect to the daily light and temperature cycles.