果蝇昼夜生理节律之细胞质PER-TIM间隔定时器的大聚合物模型

A big cluster model of the PER-TIM interval timer in drosophila cytoplasm for the circadian clock

昼夜生理节律使得生物体的生理和行为能够适应外界环境的昼夜循环变化.实验发现在果蝇的细胞质中存在由PER-TIM复合体组成的间隔计时器.本文提出了这个间隔定时器的一种可能的数学模型.模型的特点是大聚合物,快速交换,不同磷酸化位点有不同功能.模拟结果基本与实验相符,符合PER-TIM间隔定时器的主要时间特征并重现了per^L变异细胞系中定时器的特点,以及PER和TIM蛋白进入细胞核的三种不同类型的过程.

Circadian rhythm makes physiology and behaviors of organisms adapt to the day and night cycle in the environment. Recent ex- periment indicated a PER-TIM interval timer in Drosophila melanogaster cytoplasm. In this paper, we present a possible mathematical model for this interval timer. The characters of the model are the formation of big clusters, fast exchange and different functions of phosphorylation of different sites. The experimental results on features of the PER-TIM interval timer of mild type and perL mutant and on the existence of three different types of temporal profiles of nuclear accumulation of PER and TIM in single cells are reproduced by our simulations.