Figure 1.
Preparation of RETRObac and a schematic diagram illustrating BAC retrofitting. The plasmid pBGLS contains the genes GFP, neo,and lacZ. AscI digestion of pBGLS followed by gel purification of the 7.5-kb fragment and its subsequent ligation results in the final retrofitting construct RETRObac, which lacks the bacterial origin of replication. Recombination between RETRObac and a BAC clone at theloxP sites leads to integration of all of RETRObac into the BAC clone, leaving the genomic insert unaltered. The approximate positions of PCR primers Bac-F, Bac-R, and Lac-R are indicated. Constructs are not drawn to scale.
