Institute for Research in Biomedicine (IRB Barcelona), Baldiri Reixac 10-12, 08028 Barcelona, Spain, Joint IRB-BSC Program in Computational Biology, Baldiri Reixac 10-12, 08028 Barcelona, Spain and Department of Biochemistry and Molecular Biology. University of Barcelona, 08028 Barcelona, Spain.
Nucleic Acids Res. 2014 Apr;42(8):4934-46. doi: 10.1093/nar/gku165. Epub 2014 Feb 27.
Nucleosome organization plays a key role in the regulation of gene expression. However, despite the striking advances in the accuracy of nucleosome maps, there are still severe discrepancies on individual nucleosome positioning and how this influences gene regulation. The variability among nucleosome maps, which precludes the fine analysis of nucleosome positioning, might emerge from diverse sources. We have carefully inspected the extrinsic factors that may induce diversity by the comparison of microccocal nuclease (MNase)-Seq derived nucleosome maps generated under distinct conditions. Furthermore, we have also explored the variation originated from intrinsic nucleosome dynamics by generating additional maps derived from cell cycle synchronized and asynchronous yeast cultures. Taken together, our study has enabled us to measure the effect of noise in nucleosome occupancy and positioning and provides insights into the underlying determinants. Furthermore, we present a systematic approach that may guide the standardization of MNase-Seq experiments in order to generate reproducible genome-wide nucleosome patterns.
核小体组织在基因表达调控中起着关键作用。然而,尽管核小体图谱的准确性有了显著提高,但在单个核小体定位以及这如何影响基因调控方面仍存在严重差异。核小体图谱的可变性排除了对核小体定位的精细分析,这种可变性可能源于多种来源。我们通过比较在不同条件下生成的微球菌核酸酶 (MNase)-Seq 衍生核小体图谱,仔细检查了可能导致多样性的外在因素。此外,我们还通过生成来自细胞周期同步和异步酵母培养物的额外图谱,探索了源自内在核小体动力学的变化。总之,我们的研究使我们能够测量核小体占有率和定位噪声的影响,并深入了解潜在的决定因素。此外,我们提出了一种系统的方法,可以指导 MNase-Seq 实验的标准化,以生成可重复的全基因组核小体模式。