マウスの発達中のXistの発現は,X染色体不活性化の開始における役割を示唆しています
1Section of Comparative Biology, Medical Research Council Clinical Research Centre, Harrow, England.
Cell
|January 29, 1993
まとめ
マウスXist遺伝子は,プロセスそのものに先立って,X染色体不活性化を開始します. 初期の発達におけるそのインプリント表現は,Xistが父親のX不活性化を引き起こし,Xceアレルはこの効果を調節することを示唆しています.
科学分野:
- 遺伝学 遺伝学とは
- 発達生物学 発達生物学について
- エピジェネティクス エピジェネティクス
背景:
- Xist遺伝子はX不活性化センター (Xic) に位置し,不活性X染色体から発現する.
- Xistは,X染色体不活性化 (XCI) を制御する候補遺伝子である.
研究 の 目的:
- マウスの発達中のXist遺伝子発現とX染色体不活性化の間の時間的関係を調査する.
- Xist発現がXCIの原因または結果であるかどうかを判断する.
主な方法:
- マウスモルラとブラストキスタにおけるXist遺伝子発現のタイミングの分析.
- Xistアレル特異的な発現とインプリントパターンの調査.
- XCE (X制御要素) アレルのXist発現とXCIに対する影響の検討.
主要な成果:
- X染色体の発現は,X染色体の不活性化より前に始まり,因果的な役割を示唆しています.
- 初期のXist発現が刻印され,父親のアレルに好意を示しており,これはトロフェクトダームにおける父親のX不活性化を引き起こす可能性があります.
- 強いXceアレルは, trofhectodermでインプリントされたXist発現の影響を軽減することができます.
- Xistインプリントはガストルレーション前に失われ,ランダムなX不活性化と一致します.
結論:
- Xistは,X染色体の不活性化を開始する直接的な役割を果たします.
- インプリントされたXist発現は,初期の発達における非ランダムな父親のX不活性化の原因である可能性が高い.
- Xceアレルは,インプリントされたXist発現に影響することによって,XCIのプロセスを調節します.
関連する概念動画
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The Y Chromosome Determines Maleness
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Evolution
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Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Dosage Compensation
In animals, gender is determined by the number and type of sex chromosome. For example, human females have two X chromosomes, and males have one X and one Y chromosome, whereas C.elegans with one X chromosome is a male, and the one with two X chromosomes is a hermaphrodite.
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...
X-inactivation
The human X chromosome contains over ten times the number of genes as in the Y chromosome. Since males have only one X chromosome, and females have two, one might expect females to produce twice as many of the proteins, with undesirable results.


