Efficient Deletion of Transgenic DNA from Complex Integration Locus of Rice Mediated by Cre/lox Recombination System
- Sarah K. Moorea and
- Vibha Srivastava *b
Transgenic plants may contain several DNA elements, most notably the selectable marker genes, that are not needed after the selection of the transgenic line. Using site-specific recombination system, such as Cre/lox, targeted deletion of these so-called unneeded DNA elements can be achieved. To study the efficiency of Cre/lox-mediated deletion of transgenic DNA from complex locus generated by particle bombardment, we generated two transgenic rice (Oryza sativa L.) lines that contain several copies of lox-flanked β-glucuronidase (GUS) gene (gusA) and unmarked hygromycin resistance (hpt) gene and crossed them with a Cre-expressing line. Excision of both gusA and hpt genes occurred in F1 hybrids. Molecular data demonstrated that Cre/lox recombination was initiated randomly in F1 plants leading to complete excision of all transgene fragments in somatic tissue. F2 analysis suggested that efficient excision also occurred in germline, preventing the transfer of lox-flanked genes into most of the F2 plants. Further, the excised DNA did not apparently re-integrate into the genome. Thus, Cre/lox-mediated DNA recombination in rice is highly suitable for the removal of the unneeded transgenic DNA.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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