Dynamic Reorganization of Nucleosome Positioning in Somatic Cells after Transfer into Porcine Enucleated Oocytes

作者：Chenyu Tao, Juan Li, Xia Zhang, Baobao Chen, Daming Chi, Yaqiong Zeng, Yingjie Niu, Chengfei Wang, Wei Cheng, Wangjun Wu, Zengxiang Pan, Jinmin Lian, Honglin Liu, Yi‐Liang Miao · 发表于：Stem Cell Reports · 年份：2017 · DOI：10.1016/j.stemcr.2017.06.004 · 被引用次数：11 · 研究领域：Pluripotent Stem Cells Research、CRISPR and Genetic Engineering、Reproductive Biology and Fertility

The nucleosome, the fundamental structural unit of chromatin, is a critical regulator of gene expression. The mechanisms governing changes to nucleosome occupancy and positioning during somatic cell reprogramming remain poorly understood. We established a method for generating genome-wide nucleosome maps of porcine embryonic fibroblasts (PEF), reconstructed 1-cell embryos generated by somatic cell nuclear transfer (SCNT), and fertilized zygotes (FZ) using MNase sequencing with only 1,000 cells. We found that donor PEF chromatin, especially X chromosome, became more open after transfer into porcine oocytes and nucleosome occupancy decreased in promoters but increased in the genic regions. Nucleosome arrangements around transcriptional start sites of genes with different expression levels in somatic cells tended to become transcriptionally silent in SCNT; however, some pluripotency genes adopted transcriptionally active nucleosome arrangements. FZ and SCNT had similar characteristics, unlike PEF. This study reveals the dynamics and importance of nucleosome positioning and chromatin organization early after reprogramming.