Epigenetic observations are represented by the total number of reads from a given pool of cells and the number of methylated reads, making it reasonable to model this data by a binomial distribution. There are numerous factors that can influence the probability of success in a particular region. Moreover, there is a strong spatial (alongside the genome) dependence of these probabilities. We incorporate dependence on the covariates and the spatial dependence of the methylation probability for observations from a pool of cells by means of a binomial regression model with a latent Gaussian field and a logit link function. We apply a Bayesian approach including prior specifications on model configurations. We run a mode jumping Markov chain Monte Carlo algorithm (MJMCMC) across different choices of covariates in order to obtain the joint posterior distribution of parameters and models. This also allows finding the best set of covariates to model methylation probability within the genomic region of interest and individual marginal inclusion probabilities of the covariates.
Longitudinal prediction of DNA methylation to forecast epigenetic outcomes
Department of Computer Science（计算机科学系）；The University of Manchester（曼彻斯特大学）；Singapore Institute for Clinical Sciences (SICS)（新加坡临床科学研究所）；Bioinformatics Institute (BII)（生物信息学研究所）；Agency for Science, Technology and Research (A*STAR)（科技研究局）；Lancaster Medical School（兰卡斯特医学院）；Lancaster University（兰卡斯特大学）
Bayesian Genome- and Epigenome-wide Association Studies with Gene Level Dependence
高通量遗传和表观遗传数据经常被筛选与观察到的表型的关联。例如，人们可能希望测试数十万个遗传变异或DNA甲基化位点与疾病状态的关联。这些基因组变量可以自然地根据它们编码的基因以及其他标准进行分组。然而，在这种应用中的标准实践是独立筛选，具有对多重性的普遍校正。我们提出了一种贝叶斯方法，其中一个给定的基因组变量的关联的先验概率取决于它的基因，和基因特异性的概率建模非参数。这种分层模型允许适当的基因和全基因组多重性调整，并可以被纳入到各种贝叶斯关联筛选方法中，计算复杂性的增加可以忽略不计。我们描述了一个应用程序，以筛选低级别胶质瘤和多形性胶质母细胞瘤肿瘤样本之间的DNA甲基化差异的癌症基因组图谱。软件可通过https://github.com/lockEF/BayesianScreening上的BayesianScreening for R软件包获得。
