Enhancement of gene targeting via cell cycle regulation in higher plants

基因靶向是通过内源基因组与外源DNA的同源重组实现的，外源DNA与内源基因组具有同源性。同源重组是DNA双链断裂修复机制之一。与原核生物和低等真核生物相比，高等植物的基因靶向性较少，由于同源重组频率较低，外源DNA主要通过非同源末端连接的方式整合到植物基因组中。根据细胞周期的不同，选择一种DNA修复途径将确保基因组的稳定性维持，而同源重组是在复制后阶段维持基因组稳定性的有效方法。本研究对拟南芥细胞周期调节因子突变体进行了分析，发现缺乏G1/S转变正调控因子的突变体同源重组频率较低。

Gene targeting is achieved through the homologous recombination between endogenous genome and foreign DNA, which has homology to endogenous genome. Homologous recombination is one of the DNA double strand break repair mechanism. In contrast to prokaryotes and lower eukaryotes, gene targeting is infrequent in higher plants and foreign DNA integrates into plant genome mainly via non-homologous end joining because of low homologous recombination frequency. Depend on the cell cycle phase, the choice of one of the DNA repair pathway over the other will secure genome stability maintenance and homologous recombination is an efficient way to maintain genome stability at a post-replication stage. In this study, we analyzed the Arabidopsis mutants of cell cycle regulation factors and revealed that the mutant, which lacks positive regulator of G1/S transition showed low homologous recombination frequency.