Lazopulo Andrey, Syed Sheyum
Department of Physics, University of Miami.
Department of Physics, University of Miami;
J Vis Exp. 2017 Oct 28(128):55977. doi: 10.3791/55977.
In most animals and plants, circadian clocks orchestrate behavioral and molecular processes and synchronize them to the daily light-dark cycle. Fundamental mechanisms that underlie this temporal control are widely studied using the fruit fly Drosophila melanogaster as a model organism. In flies, the clock is typically studied by analyzing multiday locomotor recording. Such a recording shows a complex bimodal pattern with two peaks of activity: a morning peak that happens around dawn, and an evening peak that happens around dusk. These two peaks together form a waveform that is very different from sinusoidal oscillations observed in clock genes, suggesting that mechanisms in addition to the clock have profound effects in producing the observed patterns in behavioral data. Here we provide instructions on using a recently developed computational method that mathematically describes temporal patterns in fly activity. The method fits activity data with a model waveform that consists of four exponential terms and nine independent parameters that fully describe the shape and size of the morning and evening peaks of activity. The extracted parameters can help elucidate the kinetic mechanisms of substrates that underlie the commonly observed bimodal activity patterns in fly locomotor rhythms.
在大多数动物和植物中，昼夜节律时钟协调行为和分子过程，并使其与每日的明暗周期同步。利用果蝇作为模式生物，人们广泛研究了这种时间控制背后的基本机制。在果蝇中，通常通过分析多天的运动记录来研究生物钟。这样的记录显示出一种复杂的双峰模式，有两个活动高峰：一个在黎明前后出现的早晨高峰，以及一个在黄昏前后出现的傍晚高峰。这两个高峰共同形成一个波形，与在生物钟基因中观察到的正弦振荡非常不同，这表明除了生物钟之外的机制在产生行为数据中观察到的模式方面具有深远影响。在这里，我们提供了关于使用一种最近开发的计算方法的说明，该方法以数学方式描述果蝇活动中的时间模式。该方法将活动数据与一个模型波形进行拟合，该模型波形由四个指数项和九个独立参数组成，这些参数完全描述了活动的早晨和傍晚高峰的形状和大小。提取的参数有助于阐明果蝇运动节律中常见的双峰活动模式背后的底物动力学机制。
