3Dゲノム,重複:ヘテロクロマティニズされた重複ゲノムの高級折り畳み原理

Spencer A Haws¹, Zoltan Simandi¹, R Jordan Barnett¹

¹Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

Cell

|July 22, 2022

まとめ

繰り返されるDNA配列はヒトゲノムの半分を占め問題を引き起こしますこのレビューでは,ゲノム折りたたみとヘテロクロマチンがこれらの繰り返しの要素にどのように影響するか調べます.

科学分野:

ゲノミクス
エピジェネティクス
分子生物学

背景:

人間のゲノムの50%近くは繰り返される配列で構成されています
これらの配列は拡張や再結合などの様々な変化に陥りゲノム機能を破壊する可能性があります
ヘテロクロマチンはゲノムの安定性や調節に重要な役割を果たします.

研究の目的:

高次クロマチンの折りたたみメカニズム,特に区画化とループ流出をレビューする.
これらの折り畳みメカニズムがヘテロクロマチンとどのように相互作用するかについて議論する.
繰り返し発生する要素とゲノム折り畳みとの関係を強調するためです

主な方法:

ゲノム組織と繰り返し要素に関する既存の文献のレビュー.
哺乳類のモデルシステムに重点を置く
H3K9me3媒介によるヘテロクロマチネーションを制御するメカニズムの分析.

主要な成果:

分割とループ挤出は,重要な高級折り畳みメカニズムです.
これらのメカニズムはヘテロクロマチンによって形作られ,影響を受けます.
クロマチンの折りたたみと重複する要素を関連付ける新しい証拠が

結論:

クロマチンの折り畳みを理解することは,繰り返しのゲノム要素の振る舞いを理解するために不可欠です.
H3K9me3媒介によるヘテロクロマチニゼーションは,重複配列の管理のための主要なメカニズムである.
繰り返しの要素とゲノム構造の相互作用を完全に解明するにはさらなる研究が必要です.

さらに関連する動画

10:40

Assembly of Nucleosomal Arrays from Recombinant Core Histones and Nucleosome Positioning DNA

Published on: September 10, 2013

22.7K

22:27

Hi-C: A Method to Study the Three-dimensional Architecture of Genomes.

Published on: May 6, 2010

409.6K

関連する概念動画

02:05

Duplication of Chromatin Structure

5.7K

The process of chromosome duplication during cell division requires genome-wide disruption and re-assembly of chromatin. The chromatin structure must be accurately inherited, reassembled, and maintained in the daughter cells to ensure lineage propagation.
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...

5.7K

02:38

Heterochromatin

14.3K

The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at...

DNA Packaging

Chromatin Packaging

Each human somatic cell contains 6 billion base pairs of DNA. Each base pair is 0.34 nm long, meaning each diploid cell contains a staggering 2 meters of DNA. This long DNA strand is packed inside a nucleus measuring only 10-20 microns in diameter with the help of specialized DNA-binding proteins called histones. Together they form a compact DNA-protein complex called chromatin. The chromatin is further compacted into higher-order structures. The highest level of compaction is achieved during...

17.0K

01:19

The Nucleosome

2.1K

Human DNA is almost two meters long. However, it is compressed inside a tiny nucleus measuring only a few microns in diameter. To make this degree of compaction possible, DNA is organized into several sequential levels so that it can 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.
In a chromosome, DNA is wound twice around a protein complex called a histone octamer core, which consists of 8 histone proteins. This...

2.1K

01:01

Euchromatin

7.2K

The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions take up more dye, appearing darker, while the less-compact areas take up less dye and appear lighter. Based on the compaction level, chromatins are classified into two primary forms – euchromatin and heterochromatin.
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...