Resolving nucleosomal positioning and occupancy with MNase-seq.

Nucleosomes are the basic unit of the three-dimensional structure of chromatin. It is now widely accepted that the positioning and occupancy of nucleosomes play important roles in fundamental genomic processes such as DNA transcription, replication and repair. Among the methods used to provide genome-wide nucleosomal positions and occupancy levels, MNase-seq has proven to be highly effective. Indeed, with this method, the nucleosomal landscapes of a variety of organisms have now been investigated, revealing both commonalities and differences. In this review, we first introduce the technical principles underlying MNase-seq, focusing on details essential to precisely resolve nucleosome positioning and occupancy. We then describe recent advances with this method, as well as future perspectives of its role in chromatin biology, with a particular focus of uncovering mechanistic insights of many disease process.核小体是染色质复杂三维结构的基本单位,它在基因组上的定位及占位在DNA转录、复制和修复等基础生物过程中发挥重要功能。在众多核小体定占位研究技术中,微球菌核酸酶测序(micrococcal nuclease sequencing, MNase-seq)被认为是目前最为高效的方法,因此应用十分广泛。研究人员利用该技术绘制了多种生物的核小体图谱,并揭示了核小体组织特点的共性和差异。本文介绍了MNase-seq的技术原理以及在解析核小体组织及其功能中的应用,总结了在染色质构象这一快速发展领域中的研究进展,并展望了染色质生物学的未来发展方向。由MNase-seq揭示的核小体组织结构为基因表达和发育调控提供了新的见解,也有助于人们理解疾病的发生过程。.