Targeted modification of a human beta-globin locus BAC clone using GET Recombination and an I-Scei counterselection cassette

Duangporn Jamsai, Michael R Orford, Mikhail Nefedov, Suthat Fucharoen, Robert Williamson, Panayiotis A Ioannou

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33 Citations (Scopus)


There is a need for better approaches to allow precise engineering of large genomic BAC DNA fragments, to facilitate the use of intact genomic loci for therapeutic and biotechnology applications. We report an efficient method to insert any modification in any genomic locus, using a human beta-globin locus BAC clone as a model system. The modifications can range from single base changes to large insertions or deletions and leave no operational sequences. A counterselection cassette, consisting of an inducible I-SceI gene, its recognition site, and an antibiotic resistance gene, is inserted into the targeted region using GET Recombination. A PCR fragment carrying the modification but no selectable marker replaces the counterselection cassette in a second round of GET Recombination. The unique I-SceI site in the counterselection cassette is cut by I-SceI endonuclease, strongly selecting against nonrecombinant clones and yielding up to 30 correct recombinants.
Original languageEnglish
Pages (from-to)68 - 77
Number of pages10
Issue number1
Publication statusPublished - 2003
Externally publishedYes

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