title: Split-Cre complementation restores combination activity on transgene excision in hair roots of transgenic tobacco.
abstract: The Cre/loxP system is increasingly exploited for genetic manipulation of DNA in vitro and in vivo. It was previously reported that inactive ''split-Cre'' fragments could restore Cre activity in transgenic mice when overlapping co-expression was controlled by two different promoters. In this study, we analyzed recombination activities of split-Cre proteins, and found that no recombinase activity was detected in the in vitro recombination reaction in which only the N-terminal domain (NCre) of split-Cre protein was expressed, whereas recombination activity was obtained when the C-terminal (CCre) or both NCre and CCre fragments were supplied. We have also determined the recombination efficiency of split-Cre proteins which were co-expressed in hair roots of transgenic tobacco. No Cre recombination event was observed in hair roots of transgenic tobacco when the NCre or CCre genes were expressed alone. In contrast, an efficient recombination event was found in transgenic hairy roots co-expressing both inactive split-Cre genes. Moreover, the restored recombination efficiency of split-Cre proteins fused with the nuclear localization sequence (NLS) was higher than that of intact Cre in transgenic lines. Thus, DNA recombination mediated by split-Cre proteins provides an alternative method for spatial and temporal regulation of gene expression in transgenic plants.
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China; Chongqing Key Laboratory of Transgenic Plant and Safety Control, Southwest University, Chongqing, China.
authors.forename: Mengling
authors.initials: M
authors.lastname: Wen
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China; Chongqing Key Laboratory of Transgenic Plant and Safety Control, Southwest University, Chongqing, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China; Chongqing Key Laboratory of Transgenic Plant and Safety Control, Southwest University, Chongqing, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China; Chongqing Key Laboratory of Transgenic Plant and Safety Control, Southwest University, Chongqing, China.
authors.forename: Lingyu
authors.initials: L
authors.lastname: Ran
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China; Chongqing Key Laboratory of Transgenic Plant and Safety Control, Southwest University, Chongqing, China.
authors.forename: Jiahui
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Eco-environments of Three Gorges Reservoir Region, Ministry of Education, Institute of Resources Botany, School of Life Sciences, Southwest University, Chongqing, China; Chongqing Key Laboratory of Transgenic Plant and Safety Control, Southwest University, Chongqing, China; Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China.
authors.forename: Keming
authors.initials: K
authors.lastname: Luo
mesh_terms: D019426:Integrases / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics*; D011995:Recombination, Genetic; D014026:Nicotiana / Q000235:genetics*; D019076:Transgenes
chemical_list: C045073:Cre recombinase; D019426:Integrases