title: Excision of a selective marker in transgenic rice using a novel Cre/loxP system controlled by a floral specific promoter.
abstract: Based on the Cre/loxP system, we have developed a novel marker-free system mediating a direct auto-excision of loxP-flanked marker genes from T(1 )transgenic rice without any treatment or further offspring crossing. To achieve this, the floral-specific promoter OsMADS45 was isolated from rice and the expression patterns of OsMADS45 promoter was characterised by using the pOs45:GUS transgenic plants. Furthermore, the binary vector with Cre recombinase under the control of OsMADS45 promoter was constructed and introduced into rice by Agrobacterium-mediated transformation and transgenic rice plants were generated. Southern blot analysis showed that auto-excision of the selective markers occurred in some T(1) progeny of the transgenic plants, suggesting that a high auto-excision frequency can be achieved with our Cre/loxP system. This auto-excision strategy provides an efficient way of removing the selectable marker gene from transgenic rice.
authors.affiliation: State Key Laboratory of Plant Genomics and National Centre for Plant Gene Research (Beijing), Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Xianquan
authors.initials: X
authors.lastname: Bai
authors.forename: Qiuyun
authors.initials: Q
authors.lastname: Wang
authors.forename: Chengcai
authors.initials: C
authors.lastname: Chu
mesh_terms: D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005819:Genetic Markers; D005821:Genetic Techniques; D019426:Integrases / Q000235:genetics* / Q000378:metabolism; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic
chemical_list: D005819:Genetic Markers; C045073:Cre recombinase; D019426:Integrases