The Rockefeller University, New York, NY, 10065, USA.
Trends Genet. 2010 Nov;26(11):476-83. doi: 10.1016/j.tig.2010.08.003. Epub 2010 Sep 9.
To achieve high compaction, most genomic DNA in eukaryotes is incorporated into nucleosomes; however, regulatory factors and transcriptional machinery must gain access to chromatin to extract genetic information. This conflict is partially resolved by a particular arrangement of nucleosome locations on the genome. Across all eukaryotic species, promoters and other regulatory sequences are more nucleosome-depleted, whereas transcribed regions tend to be occupied with well-positioned, high-density nucleosomal arrays. This nucleosome positioning pattern, as well as its dynamic regulation, facilitates the access of transcription factors to their target sites and plays a crucial role in determining the transcription level, cell-to-cell variation and activation or repression dynamics.
为实现高压缩率，真核生物中的大多数基因组 DNA 都被整合到核小体中；然而，调控因子和转录机制必须能够进入染色质以提取遗传信息。这种冲突在一定程度上可以通过基因组上核小体位置的特定排列来解决。在所有真核生物物种中，启动子和其他调控序列的核小体含量较低，而转录区域往往被位置良好、高密度的核小体阵列占据。这种核小体定位模式及其动态调节有助于转录因子与其靶位点的结合，并在决定转录水平、细胞间变异性以及激活或抑制动力学方面发挥着关键作用。
