Kerbach S, Lörz H, Becker D
Biocenter Klein Flottbek, Section Developmental Biology and Biotechnology, University of Hamburg, Ohnhorststrasse 18, 22609, Hamburg, Germany.
Theor Appl Genet. 2005 Nov;111(8):1608-16. doi: 10.1007/s00122-005-0092-2. Epub 2005 Oct 1.
The elimination of marker genes after selection is recommended for the commercial use of genetically modified plants. We compared the applicability of the two site-specific recombination systems Cre/lox and Flp/FRT for marker gene elimination in maize plants. The selection marker gene pat surrounded by two identically directed lox or FRT sites was introduced into maize. Sexual crossing with plants harboring the corresponding constitutively expressed recombinase led to the precise and complete excision of the lox-flanked marker gene in the F1 progeny, whereas Flp-mediated recombination of FRT sequences occurred rarely. Further examination of site-specific integration was done by biolistic bombardment of immature embryos harboring only one lox site with a lox.uidA sequence with results indicating directed integration.
对于转基因植物的商业应用，建议在筛选后去除标记基因。我们比较了两种位点特异性重组系统Cre/lox和Flp/FRT在玉米植株中去除标记基因的适用性。将被两个同向lox或FRT位点包围的选择标记基因pat导入玉米。与携带相应组成型表达重组酶的植株进行有性杂交，导致F1后代中lox侧翼标记基因的精确和完全切除，而Flp介导的FRT序列重组很少发生。通过用lox.uidA序列对仅含有一个lox位点的未成熟胚进行生物弹轰击来进一步检测位点特异性整合，结果表明发生了定向整合。
