Cellular reprogramming is the process during which epigenetic markers of nuclear genome are deleted and remodeled during sperm-egg binding or nuclear transplantation, thereby rendering differentiated cells totipotent. The main cellular reprogramming methods are cell fusion, somatic cell nuclear transplantation, and induced pluripotent stem cells. Nucleosomes are the basic structural and functional units of chromatin, and nucleosome localization has an important role in regulating gene expression and the state of the cell. The occupancy and location of nucleosomes also change dramatically during cellular reprogramming, while the occupancy of nucleosomes around the transcriptional start site also decreases to promote the expression of pluripotency genes. In this review, we summarize the role of nucleosome localization in gene activation and repression, chromatin remodeling, and transcription factor recognition, with the aim of providing an important basis for an in-depth analysis of cellular reprogramming mechanisms.
细胞重编程是指在精卵结合或核移植过程中,核遗传物质的表观遗传标记发生删除和重塑,从而使已分化的细胞成为具有全能性的过程。发生细胞重编程的方法主要有细胞融合、体细胞核移植以及诱导多能干细胞等。核小体是染色质的基本结构及功能单位,是染色质的一级结构,核小体定位对基因的表达及细胞的状态有着重要的调控作用。细胞重编程过程中核小体的含量和位置也会发生剧烈的变化,同时在相关基因启动子位置的核小体含量也会降低从而促进多能性基因的表达。本文综述了核小体定位在基因激活与抑制、染色质重塑以及转录因子识别中的作用,旨在为深入解析细胞重编程机制提供重要依据。.
Keywords: cellular reprogramming; chromatin remodeling; nucleosome localization; transcription initiation sites.