Department of Crop, Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR 72701, USA.
J Biosci. 2011 Mar;36(1):37-42. doi: 10.1007/s12038-011-9010-8.
The present study assessed the efficacy of a heat-inducible cre gene for conditional removal of the marker gene from a rice genome via Cre-lox recombination. A cre gene controlled by the soybean heat-shock promoter was introduced into the rice genome along with the recombination target (lox) construct. Cre-mediated recombination was expected to remove the marker gene and activate the promoter-less GUS gene. Six transgenic lines displayed well-regulated heat-inducible Cre activity in the callus. However, only one line that contained a single copy of the cre gene maintained this property in the regenerated plants and their progeny. Marker-free progeny were obtained from the plant that was heat-treated at the seedling stage, indicating the inheritance of the recombination 'footprint'. The presence of the 'footprint' was verified by polymerase chain reaction and Southern analysis. Therefore, the cre gene controlled by the soybean heat-shock promoter is an effective tool for conditional removal of the marker gene in rice.
本研究评估了热诱导 cre 基因在通过 Cre-lox 重组将标记基因从水稻基因组中条件性去除的功效。一个受大豆热激启动子控制的 cre 基因与重组靶标（lox）构建体一起被引入水稻基因组。预期 Cre 介导的重组将去除标记基因并激活无启动子的 GUS 基因。六个转基因系在愈伤组织中显示出良好的热诱导 cre 活性。然而，只有一条含有单个 cre 基因的系在再生植物及其后代中保持了这种特性。从在幼苗期进行热处理的植物中获得了无标记的后代，表明重组“足迹”的遗传。通过聚合酶链反应和 Southern 分析验证了“足迹”的存在。因此，受大豆热激启动子控制的 cre 基因是在水稻中条件性去除标记基因的有效工具。
