基于大小的预期最大化,用于表征核位和亚型.
Jianyu Yang1, Kuangyu Yen2,3, Shaun Mahony4
1Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Genome research
|June 17, 2024
概括
一个新的工具,基于大小的预期最大化 (SEM),分析MNase-seq数据以识别不典型的核细胞. SEM揭示了可访问区域中的短片段核细胞,提供了对染色体调节的见解.
科学领域:
- * 基因组学 是一个学科.
- * 分子生物学 * 分子生物学
- * 生物信息学是一门学科.
背景情况:
- * 核形状通常使用MNase-seq,假设统一的147bp DNA保护.
- * 具有较短DNA保护的非典型核细胞被标准分析包所忽视.
- * 了解不同的核细胞类型对于破译基因调节至关重要.
研究的目的:
- * 引入基于大小的预期最大化 (SEM) 包用于核细胞分析.
- * 能够从MNase-seq数据中表征各种核酶子类型.
- * 克服现有的核细胞组调用工具中刚性假设的局限性.
主要方法:
- * 开发了SEM,一个使用层次高斯混合模型的包.
- *利用SEM估计核细胞位,并根据DNA片段长度分布自动识别亚型.
- *使用基准数据集对现有包进行验证的SEM性能.
主要成果:
- * SEM实现了与标准包相比的准确性,同时能够独特地识别核子亚型.
- * 应用于MNase-H2B-ChIP-seq数据,SEM确定了短片段,正规和二核酶体.
- * 基于染色体可访问性,对短片段核细胞的两种亚型进行了表征,可访问的亚型在TSS和CTCF站点进行了丰富.
结论:
- * SEM提供了一个强大的平台来探索非正规的核细胞子类型.
- * 通过SEM识别的可访问的短片段核细胞在调节区域中普遍存在,并与染色体重塑剂相关.
- *这项工作增强了研究核细胞异质性及其监管影响的能力.
相关概念视频
The Nucleosome Core Particle
12.1K
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
12.1K
Chromatin Position Affects Gene Expression
23.3K
Chromatin is the massive complex of DNA and proteins packaged inside the nucleus. The complexity of chromatin folding and how it is packaged inside the nucleus greatly influences access to genetic information. Generally, the nucleus' periphery is considered transcriptionally repressive, while the cell's interior is considered a transcriptionally active area.
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the...
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the...
23.3K
Position-effect Variegation
6.3K
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
6.3K
Nucleosome Remodeling
9.1K
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
9.1K
The Nucleosome
16.2K
DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside the nucleus is astonishing. It is organized into several sequentially higher levels of compaction to fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
16.2K
Chromatin Packaging
15.3K
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order...
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order...
15.3K


