Photic entrainment of period mutant mice is predicted from their phase response curves.
Photic entrainment of period mutant mice is predicted from their phase response curves.
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DOI：
10.1523/jneurosci.2607-10.2010
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发表时间：
2010-09-08
期刊：
影响因子：
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通讯作者：
Yamazaki S
中科院分区：
文献类型：
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作者：
Pendergast JS;Friday RC;Yamazaki S
生物钟的一个基本特性是它们会受到环境线索的影响。昼夜节律基因Period 1和Period 2参与哺乳动物昼夜节律系统的夹带。为了研究Period基因在光诱导中的作用，我们构建了C57 BL/6 J野生型、Per 1 −/−、Per 2 −/−和Per 3 −/−小鼠对光脉冲的相位响应曲线（PRC），并测试了PRC是否准确预测了对非24亮暗周期（T周期）和恒定光（LL）的诱导。野生型和Per 3 −/−小鼠的PRC在形状和振幅上相似，具有相对较大的延迟区和较小的提前区，导致成功夹带到T26，但不是T21，具有相似的相位角。Per 1 −/−小鼠具有高幅度的PRC，导致广泛的T周期夹带。Per 2 −/−小鼠也参与了广泛的T周期，因为它们的PRC的提前部分比野生型更大。在所有基因型中，夹带到T周期后的时期后效相似。我们发现，PRC的提前部分与延迟部分的比值准确地预测了LL活动节律周期的延长。野生型、Per 1 −/−和Per 3 −/−小鼠在LL中的延迟区比提前区更大，并且周期延长（> 24小时），而Per 2 −/−小鼠在LL中的延迟区和提前区大小相等，并且没有周期延长。总之，这些结果表明，PRCs是预测和理解昼夜节律突变小鼠的光夹带的有力工具。
A fundamental property of circadian clocks is that they entrain to environmental cues. The circadian genes, Period1 and Period2, are involved in entrainment of the mammalian circadian system. To investigate the roles of the Period genes in photic entrainment, we constructed phase response curves (PRC) to light pulses for C57BL/6J wild-type, Per1−/−, Per2−/−, and Per3−/− mice and tested whether the PRCs accurately predict entrainment to non-24 light-dark cycles (T-cycles) and constant light (LL). The PRCs of wild-type and Per3−/− mice are similar in shape and amplitude and have relatively large delay zones and small advance zones, resulting in successful entrainment to T26, but not T21, with similar phase angles. Per1−/− mice have a high-amplitude PRC, resulting in entrainment to a broad range of T-cycles. Per2−/− mice also entrain to a wide range of T-cycles because the advance portion of their PRC is larger than wild-types. Period aftereffects following entrainment to T-cycles were similar among all genotypes. We found that the ratio of the advance portion to the delay portion of the PRC accurately predicts the lengthening of the period of the activity rhythm in LL. Wild-type, Per1−/−, and Per3−/− mice had larger delay zones than advance zones and lengthened (>24hrs) periods in LL, while Per2−/− mice had delay and advance zones that were equal in size and no period lengthening in LL. Together, these results demonstrate that PRCs are powerful tools for predicting and understanding photic entrainment of circadian mutant mice.