Adaptive temperature compensation in circadian oscillations.
Adaptive temperature compensation in circadian oscillations.
复制标题
DOI：
10.1371/journal.pcbi.1002585
复制
发表时间：
2012
影响因子：
4.3
通讯作者：
Siggia ED
中科院分区：
文献类型：
--
作者：
François P;Despierre N;Siggia ED
温度无关周期和温度夹带是昼夜节律振荡器的两个定义特征。分布式温度补偿的默认模型满足这些基本事实，但不容易与生物钟的其他特性相协调，例如许多突变体具有改变但温度补偿的周期。默认模型还表明，昼夜节律极限环的形状和相关的相位响应曲线（PRC）将有所不同，因为时钟蛋白的平均浓度随温度而变化。我们提出了另一类模型，其中固定周期和夹带的双属性是结构性的，并且来自于缓冲温度变化的底层自适应系统。这些模型的特点是PRC的形状是温度无关的和轨道的极值是温度无关的。它们很容易通过局部、爬山、基因网络优化来进化，以实现生物钟的共同质量测量、相位预测。有趣的是，用于温度补偿的Goodwin模型的标准实现显示自适应而不是分布式温度补偿的特性。昼夜节律钟是生物振荡器，它进化到将动物、植物甚至一些细菌的内部节奏与光和日的交替相耦合。昼夜节律振荡器是温度补偿的，即它们保持24小时的周期，而与生物体的温度无关。这是令人惊讶的，因为许多生物化学参数，包括时钟蛋白的平均浓度，随温度而变化。因此，从动力系统理论出发，我们预期相位响应曲线中的特征的周期和相对长度都会发生变化，而这些变化是看不到的。我们耦合数学建模和计算进化的基因网络，制定一个新的解释温度补偿，符合实验事实比替代品。我们的模型与生物化学适应过程有着深刻的数学联系，细胞对信号的时间梯度而不是绝对值做出反应。
A temperature independent period and temperature entrainment are two defining features of circadian oscillators. A default model of distributed temperature compensation satisfies these basic facts yet is not easily reconciled with other properties of circadian clocks, such as many mutants with altered but temperature compensated periods. The default model also suggests that the shape of the circadian limit cycle and the associated phase response curves (PRC) will vary since the average concentrations of clock proteins change with temperature. We propose an alternative class of models where the twin properties of a fixed period and entrainment are structural and arise from an underlying adaptive system that buffers temperature changes. These models are distinguished by a PRC whose shape is temperature independent and orbits whose extrema are temperature independent. They are readily evolved by local, hill climbing, optimization of gene networks for a common quality measure of biological clocks, phase anticipation. Interestingly a standard realization of the Goodwin model for temperature compensation displays properties of adaptive rather than distributed temperature compensation. Circadian clocks are biological oscillators which evolved to couple the internal rhythm of animals, plants and even some bacteria to the alternation of light and day. Circadian oscillators are temperature compensated, i.e. they keep a 24-h period irrespective of the temperature of the organism. This is surprising, since many biochemical parameters, including average concentration of clock proteins, vary with temperature. From dynamical system theory, we therefore expect changes in both period and relative lengths of features in the phase response curve which are not seen. We couple mathematical modelling and computational evolution of gene networks to formulate a novel explanation for temperature compensation that accords better with experimental facts than alternatives. Our model has deep mathematical connections with the process of biochemical adaptation, by which cells respond to temporal gradients of signals rather than their absolute value.
登录
查看更多内容
DOI：
10.1196/annals.1417.006
发表时间：
2008-01-01
期刊：
MOLECULAR AND BIOPHYSICAL MECHANISMS OF AROUSAL, ALERTNESS, AND ATTENTION
影响因子：
--
作者：
Boothroyd, Catharine E.;Young, Michael W.
通讯作者：
Young, Michael W.
影响因子：
64.5
作者：
Mehra A;Shi M;Baker CL;Colot HV;Loros JJ;Dunlap JC
通讯作者：
Dunlap JC
影响因子：
56.9
作者：
Naidoo, N;Song, W;Sehgal, A
通讯作者：
Sehgal, A
影响因子：
3.4
作者：
François, P
通讯作者：
François, P
DOI：
10.1073/pnas.0601378104
发表时间：
2007-01-23
影响因子：
11.1
作者：
Hong, Christian I.;Conrad, Emery D.;Tyson, John J.
通讯作者：
Tyson, John J.