Carroll Dana
Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, USA.
Methods Mol Biol. 2004;262:195-207. doi: 10.1385/1-59259-761-0:195.
In essentially all organisms, double-strand breaks in chromosomal DNA stimulate repair by multiple mechanisms, including homologous recombination. It is possible to use site-specific reagents to produce a break or other recombinagenic damage at a unique site, which makes possible detailed analysis of the repair products. In addition, targeted mutagenesis and gene replacement are stimulated in the immediate vicinity of the break site. To utilize meganucleases with long recognition sequences, it is necessary to introduce the corresponding sequence prior to directed cleavage. The same is typically true of triplex-forming oligonucleotides that target polypurine-polypyrimidine tracts. Zinc-finger nucleases have the potential of being targetable to arbitrarily selected sites, owing to the flexibility of zinc finger recognition of DNA.
在基本上所有的生物体中，染色体DNA中的双链断裂会通过多种机制刺激修复，包括同源重组。利用位点特异性试剂在独特位点产生断裂或其他重组性损伤是可行的，这使得对修复产物进行详细分析成为可能。此外，在断裂位点的紧邻区域会刺激靶向诱变和基因置换。要使用具有长识别序列的巨型核酸酶，有必要在定向切割之前引入相应序列。对于靶向聚嘌呤 - 聚嘧啶序列的三链形成寡核苷酸，通常也是如此。由于锌指对DNA识别的灵活性，锌指核酸酶有潜力靶向任意选择的位点。
