利用Cre/loxP系统删除转Bt基因水稻中的选择标记基因

来源于噬菌体P1的Cre/loxP位点特异性重组系统是目前在植物遗传转化中应用较多,较成熟的一个标记基因删除系统。在这个系统中,Cre酶可以特异性的识别和切割位于两个lox位点之间的标记基因,整个系统重组仅需Cre和lox识别位点即可完成而无需其它辅因子的参加。利用农杆菌介导法成功地将cre基因导入供试材料"皖粳97",得到转hpt-cre基因水稻植株;将其与先期转基因育成的携带loxp-hpt-loxp-bt基因的"皖粳97"株系进行田间杂交,通过PCR分析,Cre/loxP重组系统定向删除了潮霉素抗性筛选标记基因。

Using Cre/loxP system to excise marker gene in Bt-transgenic rice

Cre/loxP recombination system derived from bacteriophage P1 is an effective positioning mark to delete system.In this system,Cre enzyme can recognize and cut specific sites located between the two lox marker gene.The entire system including the Cre enzyme and lox recognition sites can be completed without the participation of other cofactors.In order to eliminate the targeted hygromycin selectable marker gene by using Cre/loxP recombination system,plant expression vector harboring cre gene was successfully introduced into rice Wanjing 97（Japonica Sativa L.） mediated by Agrobacterium,the transgenic plants were gained and confirmed by PCR analysis.The transgenic plants were crossed with transgenic Wanjing 97 carrying loxp-hpt-loxp-bt gene previously bred.Based on PCR analysis,the cre gene might be expressed and could carry out the deletion of the selectable marker gene.