title: Tissue-specifically regulated site-specific excision of selectable marker genes in bivalent insecticidal, genetically-modified rice.
abstract: Marker-free, genetically-modified rice was created by the tissue-specifically regulated Cre/loxP system, in which the Cre recombinase gene and hygromycin phosphotransferase gene (hpt) were flanked by two directly oriented loxP sites. Cre expression was activated by the tissue-specific promoter OsMADS45 in flower or napin in seed, resulting in simultaneous excision of the recombinase and marker genes. Segregation of T1 progeny was performed to select recombined plants. The excision was confirmed by PCR, Southern blot and sequence analyses indicating that efficiency varied from 10 to 53 % for OsMADS45 and from 12 to 36 % for napin. The expression of cry1Ac and vip3A was detected by RT-PCR analysis in marker-free transgenic rice. These results suggested that our tissue-specifically regulated Cre/loxP system could auto-excise marker genes from transgenic rice and alleviate public concerns about the security of GM crops.
authors: College of Life Science, Hunan Normal University, State Key Laboratory Breeding Base of Microbial Molecular Biology, Changsha, 410081, People's Republic of China, 309594397@qq.com.
authors: Zhan
authors: Z
authors: Hu
authors: Xuezhi
authors: X
authors: Ding
authors: Shengbiao
authors: S
authors: Hu
authors: Yunjun
authors: Y
authors: Sun
authors: Liqiu
authors: L
authors: Xia
mesh_terms: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics; D003001:Cloning, Molecular; D004731:Endotoxins / Q000235:genetics; D017343:Genes, Plant / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics*; D005822:Genetic Vectors / Q000235:genetics; D006460:Hemolysin Proteins / Q000235:genetics; D019426:Integrases / Q000235:genetics; D012275:Oryza / Q000235:genetics*; D010572:Pest Control, Biological / Q000379:methods*; D030821:Plants, Genetically Modified / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D005819:Genetic Markers; D006460:Hemolysin Proteins; C447139:Vip3A protein, Bacillus thuringiensis; C030956:insecticidal crystal protein, Bacillus Thuringiensis; C045073:Cre recombinase; D019426:Integrases