title: Rapid engineering of bacterial artificial chromosomes using oligonucleotides.
abstract: A rapid method obviating the use of selectable markers to genetically manipulate large DNA inserts cloned into bacterial artificial chromosomes is described. Mutations such as single-base changes, deletions, and insertions can be recombined into a BAC by using synthetic single-stranded oligonucleotides as targeting vectors. The oligonucleotides include the mutated sequence flanked by short homology arms of 35-70 bases on either side that recombine with the BAC. In the absence of any selectable marker, modified BACs are identified by specific PCR amplification of the mutated BAC from cultures of pooled bacterial cells. Each pool represents about 10 electroporated cells from the original recombination mixture. Subsequently, individual clones containing the desired alteration are identified from the positive pools. Using this BAC modification method, we have observed a frequency of one recombinant clone per 90-260 electroporated cells. The combination of high targeting frequency and the sensitive yet selective PCR-based screening method makes BAC manipulation using oligonucleotides both rapid and simple.
authors.affiliation: Mouse Cancer Genetics Program, National Cancer Institute-Frederick, Frederick, Maryland 21702-1201, USA.
authors.forename: S
authors.initials: S
authors.lastname: Swaminathan
authors.forename: H M
authors.initials: HM
authors.lastname: Ellis
authors.forename: L S
authors.initials: LS
authors.lastname: Waters
authors.forename: D
authors.initials: D
authors.lastname: Yu
authors.forename: E C
authors.initials: EC
authors.lastname: Lee
authors.forename: D L
authors.initials: DL
authors.lastname: Court
authors.forename: S K
authors.initials: SK
authors.lastname: Sharan
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D020137:Base Pair Mismatch; D001483:Base Sequence; D015139:Blotting, Southern; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics*; D003001:Cloning, Molecular / Q000379:methods*; D017931:DNA Primers / Q000737:chemistry; D005090:Exodeoxyribonucleases / Q000378:metabolism*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D009841:Oligonucleotides / Q000737:chemistry*; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D009841:Oligonucleotides; D005090:Exodeoxyribonucleases