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Updated: May 12, 2026

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Published on: September 7, 2017
CTCFは,H19/Igf2ロカスにおけるメチレーションに敏感な増強剤阻害活性を媒介する
A T Hark1, C J Schoenherr, D J Katz
1Howard Hughes Medical Institute and Department of Molecular Biology, Princeton University, New Jersey 08544, USA.
Nature
|June 6, 2000
まとめ
H19の近くのインプリント制御領域は境界線として作用し,遺伝子相互作用をブロックします. この領域へのCTCF結合は,遺伝子の静止を防ぐが,メチル化はこの境界関数を破壊する.
科学分野:
- 遺伝学 遺伝学とは
- エピジェネティクス エピジェネティクス
- ゲノムインプリントング (Genomic Imprinting) とは
背景:
- インスリン類似成長因子2 (Igf2) とH19遺伝子は,母性および父性アレルの差異的な静音化により,ゲノムインプリントの対象となります.
- このインプリントは,アレル固有の遺伝子発現に重要な上流インプリント制御領域 (ICR) によって制御されます.
研究 の 目的:
- Igf2とH19の遺伝子発現を調節するH19 ICRの機能を調査する.
- ICR媒介遺伝子調節におけるDNAメチル化とCTCF結合の役割を決定する.
主な方法:
- トランスジェニックマウスと組織培養モデルを使用した.
- H19 ICR.の強化剤阻害作用を評価した.
- CTCFとICRの結合と,DNAメチル化が結合と機能に与える影響について研究した.
主要な成果:
- ネズミとヒトからの非メチル化H19ICRがエンハンサー阻害活性を持っていることを実証した.
- ICR内の特定されたCTCF結合部位は,このエンハンサーブロック機能に不可欠です.
- DNAメチル化がCTCF結合をなくし,その結果,エンハンサーを阻害する活動を廃止することを示した.
結論:
- 非メチル化ICRは,CTCF結合によって媒介される,調節されたクロマチンの境界線として機能する.
- DNAメチル化はCTCF結合を妨げ,境界機能の喪失につながり,父親のIgf2発現を可能にします.
- この研究は,ゲノムインプリントに関与する脊椎動物クロマチンの規制された境界の最初の例を示しています.
関連する概念動画
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Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
Inheritance of Chromatin Structures
Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying DNA...
Cis-regulatory Sequences
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...
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Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
Genomic Imprinting and Inheritance
Diploid organisms inherit genetic material through chromosomes from both parents. Copies of the same gene are known as alleles. In most cases, both alleles are simultaneously expressed and allow various cellular processes to function optimally. If one of the alleles is missing or mutated, the expression of the other allele can compensate; however, this is not true for all genes.
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
The expression of some genes depends on which parent passed the gene to the offspring, through a phenomenon known as...
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...

