A Locally Convoluted Cluster Model for Nucleosome Positioning Signals in Chemical Maps

作者:Xi Liqun; Brogaard Kristin; Zhang Qingyang; Lindsay Bruce; Widom Jonathan; Wang Ji Ping*
来源:Journal of the American Statistical Association, 2014, 109(505): 48-62.
DOI:10.1080/01621459.2013.862169

摘要

The nucleosome is the fundamental packing unit of DNA in eukaryotic cells, and its positioning plays a critical role in regulation of gene expression and chromosome functions. Using a recently developed chemical mapping method, nucleosomes can be potentially mapped with an unprecedented single-base-pair resolution. Existence of overlapping nucleosomes due to cell mixture or cell dynamics, however, causes convolution of nucleosome positioning signals. In this article, we introduce a locally convoluted cluster model and a maximum likelihood deconvolution approach, and illustrate the effectiveness of this approach in quantification of the nucleosome positional signal in the chemical mapping data. Supplementary materials for this article are available online.