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arXiv 1402.0042q-bio.GN
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motifDiverge:一种用于评估两个DNA序列之间基因调控基序差异的统计学显著性的模型

motifDiverge: a model for assessing the statistical significance of gene regulatory motif divergence between two DNA sequences

Dennis Kostka, Tara Friedrich, Alisha K. Holloway, Katherine S. Pollard

摘要:

下一代测序技术能够识别许多细胞类型和生物体中的数千个基因调控序列。我们考虑的问题,如果两个这样的序列不同的结合位点图案的数量为一个给定的转录因子(TF)蛋白的测试。结合位点基序通过提供TF与基因组元件结合的机会并由此影响附近基因的表达而赋予调节功能。这些功能DNA的进化变化被假设为是物种内和物种间表型多样性的主要贡献者;但是,尽管TF基序对基因表达很重要,但还没有方法来测试基序的丢失或获得。假设基序计数是二项分布的,并允许在进化相关序列中基序实例之间的依赖性,我们推导出两个核苷酸序列之间基序计数差异的概率质量函数。我们提供了一种方法来从基因组数据中数值估计这种分布,并通过模拟表明我们的估计是准确的。最后,我们介绍了R包{ \tt motifDiverge},实现我们的方法,并说明其应用程序的基因调控增强子确定的小鼠发育时程实验。虽然这项研究的动机是分析的监管图案,我们的研究结果可以适用于任何问题,涉及两个相关的伯努利试验。

英文摘要:

Next-generation sequencing technology enables the identification of thousands of gene regulatory sequences in many cell types and organisms. We consider the problem of testing if two such sequences differ in their number of binding site motifs for a given transcription factor (TF) protein. Binding site motifs impart regulatory function by providing TFs the opportunity to bind to genomic elements and thereby affect the expression of nearby genes. Evolutionary changes to such functional DNA are hypothesized to be major contributors to phenotypic diversity within and between species; but despite the importance of TF motifs for gene expression, no method exists to test for motif loss or gain. Assuming that motif counts are Binomially distributed, and allowing for dependencies between motif instances in evolutionarily related sequences, we derive the probability mass function of the difference in motif counts between two nucleotide sequences. We provide a method to numerically estimate this distribution from genomic data and show through simulations that our estimator is accurate. Finally, we introduce the R package {\tt motifDiverge} that implements our methodology and illustrate its application to gene regulatory enhancers identified by a mouse developmental time course experiment. While this study was motivated by analysis of regulatory motifs, our results can be applied to any problem involving two correlated Bernoulli trials.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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