Vaillant C, Audit B, Arneodo A
Laboratoire Joliot-Curie and Laboratoire de Physique, CNRS, ENS-Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
Phys Rev Lett. 2007 Nov 23;99(21):218103. doi: 10.1103/PhysRevLett.99.218103. Epub 2007 Nov 21.
From the statistical analysis of nucleosome positioning data for chromosome III of S. cerevisiae, we demonstrate that long-range correlations (LRC) in the genomic sequence strongly influence the organization of nucleosomes. We present a physical explanation of how LRC may significantly condition the overall formation and positioning of nucleosomes including the nucleosome-free regions observed at gene promoters. From grand canonical Monte Carlo simulations based upon a simple sequence-dependent nucleosome model, we show that LRC induce a patchy nucleosome occupancy landscape with alternation of "crystal-like" phases of confined regularly spaced nucleosomes and "fluidlike" phases of rather diluted nonpositioned nucleosomes.
通过对酿酒酵母第三条染色体的核小体定位数据进行统计分析，我们证明基因组序列中的长程相关性（LRC）对核小体的组织有强烈影响。我们提出了一种物理解释，说明LRC如何显著影响核小体的整体形成和定位，包括在基因启动子处观察到的无核小体区域。基于一个简单的序列依赖性核小体模型进行的巨正则蒙特卡罗模拟表明，LRC诱导出一种斑驳的核小体占据格局，其中有受限的规则间隔核小体的“晶体状”相和相当稀释的无定位核小体的“流体状”相交替出现。
