The Institute of Statistical Mathematics, Research Organization of Information and Systems, Tokyo, Japan.
Bioinformatics. 2010 Sep 15;26(18):i589-95. doi: 10.1093/bioinformatics/btq389.
Biochemical reactions in cells are made of several types of biological circuits. In current systems biology, making differential equation (DE) models simulatable in silico has been an appealing, general approach to uncover a complex world of biochemical reaction dynamics. Despite of a need for simulation-aided studies, our research field has yet provided no clear answers: how to specify kinetic values in models that are difficult to measure from experimental/theoretical analyses on biochemical kinetics.
We present a novel non-parametric Bayesian approach to this problem. The key idea lies in the development of a Dirichlet process (DP) prior distribution, called Bayesian experts, which reflects substantive knowledge on reaction mechanisms inherent in given models and experimentally observable kinetic evidences to the subsequent parameter search. The DP prior identifies significant local regions of unknown parameter space before proceeding to the posterior analyses. This article reports that a Bayesian expert-inducing stochastic search can effectively explore unknown parameters of in silico transcription circuits such that solutions of DEs reproduce transcriptomic time course profiles.
A sample source code is available at the URL http://daweb.ism.ac.jp/~yoshidar/lisdas/.
细胞中的生化反应由几种类型的生物电路组成。在当前的系统生物学中,制作可在计算机中进行微分方程 (DE) 模拟的模型是揭示生化反应动力学复杂世界的一种有吸引力的通用方法。尽管需要进行模拟辅助研究,但我们的研究领域尚未提供明确的答案:如何在难以通过生化动力学的实验/理论分析来测量的模型中指定动力学值。
我们提出了一种解决该问题的新的非参数贝叶斯方法。关键思想在于开发一个 Dirichlet 过程 (DP) 先验分布,称为贝叶斯专家,它反映了给定模型中固有的反应机制和实验可观察的动力学证据的实质性知识,以便随后进行参数搜索。DP 先验在进行后验分析之前确定未知参数空间的重要局部区域。本文报告称,贝叶斯专家诱导的随机搜索可以有效地探索计算机转录电路的未知参数,从而使 DE 的解再现转录组时间过程谱。
可在 URL http://daweb.ism.ac.jp/~yoshidar/lisdas/ 获得示例源代码。