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Recombineering Homologous Recombination Constructs in Drosophila
Published on: July 13, 2013
添加与端粒相关的HeT DNA序列"治愈"Drosophila中断裂的染色体末端
H Biessmann1, J M Mason, K Ferry
1Developmental Biology Center, University of California, Irvine 92717.
Cell
|May 18, 1990
概括
果有破碎的X染色体 (RT染色体) 要么丢失DNA,要么通过将HeT DNA序列添加到末端来治愈. 这种愈合过程发生在没有同源重组的情况下,这表明了特定的DNA修复机制.
科学领域:
- 遗传学 是一个遗传学.
- 分子生物学分子生物学
- 德洛索菲拉 (Drosophila melanogaster) 的研究研究
背景情况:
- 保持了具有终端缺失 (RT染色体) 的Drosophila melanogaster X染色体的库存.
- 一些RT染色体表现出来自断端的渐进性DNA损失,与不完整的复制相一致.
- 其他RT染色体显示没有添加与端粒相关的DNA到退缩的末端.
研究的目的:
- 调查Drosophila melanogaster X染色体中DNA损失和愈合的机制,其中包括终端删除.
- 为了确定参与染色体断裂的愈合过程中的DNA序列.
- 阐明获得新的端粒序列的过程.
主要方法:
- 维护和观察D. melanogaster X染色体库存与终端删除多年.
- 对染色体的DNA序列分析结束,以确定添加的序列和结点.
- 在新DNA和破裂染色体末端的结合处的序列的比较.
主要成果:
- 两个股票显示"治愈"的RT染色体,停止了DNA损失.
- 治愈的染色体末端获得了HeT DNA的段落,这是一个复杂的重复家族,通常存在于端粒和周心 heterochromatin.
- 尽管有不同的断裂点,但添加到断裂端的HeT DNA序列在两种库存中都是相同的.
- 序列分析显示,在原始断裂端和新获得的DNA之间的结点上没有可检测的序列相似性,这表明存在非同源的重组机制.
结论:
- 破裂染色体的愈合在D. melanogaster的RT染色体中结束,涉及到HeT DNA序列的特定添加.
- 这种端粒添加机制似乎不涉及同源重组.
- 这些发现表明,在缺少功能端粒的情况下,保持染色体完整性的特殊DNA修复途径.
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