Figure 2 .

Long-range SIRT. In step 1, a recombineered vector (pP[Walkman]) containing the modified region of interest, an attB site (53 bp), an I-SceI recognition site (18 bp), two FRT sites (34 bp), and two P-element ends (100–500 bp) is injected into stocks that contain an attP site within ~70 kb of the region of interest. Recombination between attP and attB results in attL and attR sites flanking the insertion. In step 2, a double-strand break is induced at the I-SceI site, and repair of that break results in collapse of the duplication. Either the modified or the endogenous region of interest can be retained. The pP[Walkman] backbone can be removed through a FLP/FRT recombination reaction.