哺乳动物大脑发育期间的全球表观基因组重构
Ryan Lister1,2, Eran A Mukamel3, Joseph R Nery1
1Genomic Analysis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
概括
在大脑发育过程中,DNA甲基化模式发生显著变化,非CG甲基化 (mCH) 在人类神经元中占主导地位. 这项研究绘制了整个生命周期中的这些动态变化,揭示了对学习和记忆的洞察力.
科学领域:
- 神经科学是一个神经科学.
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 基因组学就是基因组学.
背景情况:
- DNA甲基化在哺乳动物大脑发育,可塑性,学习和记忆中起着至关重要的作用.
- 了解DNA甲基化在整个生命周期中的动态变化对于理解大脑功能至关重要.
研究的目的:
- 为了全面地绘制全基因组组成,模式,细胞特异性和DNA甲基化动态,在人类和小鼠前皮层的单基分辨率下,在整个生命周期内全面地绘制基因组组成,模式,细胞特异性和DNA甲基化动态.
- 研究非CG甲基化 (mCH) 和5-基甲基酸 (hmC) 在神经元发育和基因调节中的作用.
主要方法:
- 全基因组双硫酸盐测序 (WGBS) 用于在单基分辨率下进行DNA甲基化分析.
- 在人类和小鼠前皮层中对不同寿命阶段的DNA甲基化动态的分析.
- 单基分辨率的5-基甲基细胞素 (hmC) 映射.
主要成果:
- 广泛的甲基组重构发生在胎儿到年轻成人的发育过程中,与突触生成 (synaptogenesis) 相一致.
- 高度保守的非CG甲基化 (mCH) 在神经元中积累,成为人类神经元基因组中占主导地位的甲基化形式.
- 一个mCH签名被确定为基因逃脱X染色体不活化.
- 在成人大脑中,hMC标记着胎儿大脑细胞基因组在CG脱甲基并激活的调节区域.
- 在hMC位点的CG脱甲基化中,Tet2活性至关重要.
结论:
- 动态DNA甲基化变化,特别是神经元mCH的积累,在大脑发育和协同生成过程中至关重要.
- 这些发现为了解神经元功能,学习和记忆的表观遗传调节提供了全面的资源.
- 这项研究强调了mCH和hMC在神经元表观基因组中的不同作用,以及它们对特定酶活性 (如Tet2.2) 的依赖.
更多相关视频
相关概念视频
Chromatin Modification in iPS Cells
Chromatin modification alters gene expression; therefore, scientists can add histone-modifying enzymes, histone variants, and chromatin remodeling complexes to somatic cells to aid reprogramming into pluripotent stem (iPS) cells.
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
Compact chromatin makes reprogramming difficult. Enzymes, such as histone demethylases and acetyltransferases, are often added during reprogramming to loosen the chromatin, making the DNA more accessible to transcription factors. Molecules that inhibit histone...
Epigenetic Regulation
Epigenetic changes alter the physical structure of the DNA without changing the genetic sequence and often regulate whether genes are turned on or off. This regulation ensures that each cell produces only proteins necessary for its function. For example, proteins that promote bone growth are not produced in muscle cells. Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
X-chromosome...
X-chromosome...
Methods of Nuclear Reprogramming
Nuclear reprogramming is a process of transforming one cell type into an unrelated cell type by epigenetic changes that alter the cell’s original gene expression pattern. Such epigenetic changes force cells to express a different set of genes, which play a significant role in inducing transformation into other cell types. Nuclear reprogramming offers applications in reproductive cloning for livestock propagation and regenerative medicine — developing patient-specific cells for injury repair.


