ミニクロモソーム領域の減少したDNAポリテネゼーションは,ドロソフィラにおける位置効果変異を経験しています
1Howard Hughes Medical Institute Research Laboratories, Carnegie Institution of Washington, Department of Embryology, Baltimore, Maryland 21210.
Cell
|October 5, 1990
まとめ
ドロソフィラの位置効果の変動は,ポリテン細胞の異色配列の複製数の減少と関連しています. この現象は遺伝子発現に影響を及ぼし,複製の変化やヘテロクロマチンの体内除去を含む可能性があります.
科学分野:
- 遺伝学 遺伝学とは
- 分子生物学は分子生物学である.
- 発達生物学 発達生物学について
背景:
- 位置効果変異 (PEV) は,遺伝子発現が遺伝子のゲノム位置によって変化する現象です.
- ヘテロクロマチンは,典型的には遺伝子に富み,PEVに敏感ですが,その基礎となる分子メカニズムは,まだ完全に理解されていません.
研究 の 目的:
- ドロソフィラのヘテロクロマティック配列の位置効果変異とコピー数変化の関係を調べる.
- ポリテン細胞におけるヘテロクロマチンのアンダーレプリケーションの分子基盤を調査する.
主な方法:
- ドロソフィラのミニクロモソームDpの分子分析 (p) 1187
- ヘテロクロマティックとユークロマティック配列のDNAコピー番号の定量化.
- 黄色い遺伝子の遺伝子発現の分析.
主要な成果:
- ユークロマチンのブレイクポイントに隣接するヘテロクロマチンのコピーの数の有意な減少 (少なくとも60倍) が観察されました.
- ブレイクポイントから103kbまでのユークロマティックシーケンスも,コピー数の減少を示した.
- コピー数と黄色い遺伝子発現の両方もモザイクパターンを表しており,既知のPEV抑制剤であるY染色体の追加によって増加しました.
結論:
- ヘテロクロマティック配列のコピー番号の変化は,位置効果の変動と遺伝子発現の変化と相関する.
- 複製の変化は局所的にDNA複製数を変化させ,PEVに寄与する可能性があります.
- PEVの原因としてヘテロクロマティック配列の体的除去を提案する代替モデルが議論されます.
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