Müller A E, Kamisugi Y, Grüneberg R, Niedenhof I, Hörold R J, Meyer P
University of Leeds, Leeds, LS2 9JT, UK.
J Mol Biol. 1999 Aug 6;291(1):29-46. doi: 10.1006/jmbi.1999.2957.
Illegitimate recombination is the prevailing molecular mechanism for the integration of recombinant DNA into the genome of most eukaryotic systems and the generation of deletions by intrachromosomal recombination. We developed a ?selectable marker system to screen for intrachromosomal illegitimate recombination events in order to assess the sequence and structure-specific requirements for illegitimate recombination in tobacco. In 12 illegitimate recombination products analysed, we found that all deletion termini localise to sites of palindromic structures or to A+T-rich DNA elements. All deletion termini showed microhomologies of two to six nucleotides. In three plants, the recombination products contained filler-DNA or an inversion of an endogenous segment. Our data strongly suggest that illegitimate recombination in plants is mediated by a DNA synthesis-dependent process, and that this mechanism is promoted by DNA regions that can form palindromic structures or facilitate DNA unwinding.
非法重组是重组DNA整合到大多数真核系统基因组以及通过染色体内重组产生缺失的主要分子机制。我们开发了一种可选择标记系统来筛选染色体内非法重组事件，以便评估烟草中非法重组对序列和结构的特异性要求。在分析的12个非法重组产物中，我们发现所有缺失末端都定位于回文结构位点或富含A+T的DNA元件处。所有缺失末端都显示出2至6个核苷酸的微同源性。在三株植物中，重组产物包含填充DNA或内源片段的倒位。我们的数据强烈表明，植物中的非法重组是由DNA合成依赖性过程介导的，并且这种机制由能够形成回文结构或促进DNA解旋的DNA区域所促进。
