Zhao Minjun, Zhao Shunran, Pang Zhaoqi, Jia Chunhui, Tao Chenyu
College of Animal Science and Technology, Hebei Agricultural University, Baoding 071000, China.
Animals (Basel). 2024 Nov 25;14(23):3392. doi: 10.3390/ani14233392.
(1) Background: Nucleosomes represent the essential structural units of chromatin and serve as key regulators of cell function and gene expression. Oocytes in the germinal vesicle (GV) stage will later undergo meiosis and become haploid cells ready for fertilization, while somatic cells undergo mitosis after DNA replication. (2) Purpose: To furnish theoretical insights and data that support the process of cell reprogramming after nuclear transplantation. (3) Methods: We compared the nucleosome occupancy, distribution, and transcription of genes between two types of cells: fully grown GV oocytes from big follicles (BF) and somatic cells (porcine embryonic fibroblast, PEF). (4) Results: The nucleosome occupancy in the promoter of BF was 4.85%, which was significantly higher than that of 3.3% in PEF ( < 0.05), and the nucleosome distribution showed a noticeable increase surrounding transcriptional start sites (TSSs) in BF. Next, we reanalyzed the currently published transcriptome of fully grown GV oocytes and PEF, and a total of 51 genes in BF and 80 genes in PEF were identified as being uniquely expressed. The nucleosome distribution around gene TSSs correlated with expression levels in somatic cells, yet the results in BF differed from those in PEF. (5) Conclusion: This study uncovers the dynamic nature and significance of nucleosome positioning and chromatin organization across various cell types, providing a basis for nuclear transplantation.
(1) 背景：核小体是染色质的基本结构单位，是细胞功能和基因表达的关键调节因子。生发泡（GV）期的卵母细胞随后将经历减数分裂并成为准备受精的单倍体细胞，而体细胞在DNA复制后进行有丝分裂。(2) 目的：为核移植后细胞重编程过程提供理论见解和数据支持。(3) 方法：我们比较了两种细胞之间的核小体占有率、分布及基因转录情况，这两种细胞分别是来自大卵泡（BF）的完全成熟GV卵母细胞和体细胞（猪胚胎成纤维细胞，PEF）。(4) 结果：BF启动子区域的核小体占有率为4.85%，显著高于PEF的3.3%（<0.05），且BF中核小体分布在转录起始位点（TSS）周围有明显增加。接下来，我们重新分析了目前已发表的完全成熟GV卵母细胞和PEF的转录组，共鉴定出BF中51个基因和PEF中80个基因是独特表达的。基因TSS周围的核小体分布与体细胞中的表达水平相关，但BF中的结果与PEF不同。(5) 结论：本研究揭示了不同细胞类型中核小体定位和染色质组织的动态性质及意义，为核移植提供了依据。
