Fig. 2.

BIR efficiency is determined by the length of DNA to be synthesized. (A) Schematic showing the locations of the recipient and donor cassettes on Ch V and XI, respectively, and the PCR primer pairs used to detect DSB formation by HO endonuclease (D1, D2), BIR products (P1, P2), and control locus (C1, C2). (B) BIR efficiency determined by CFU Lys⁺ YPGal/CFU YPGlu for each of the indicated strains from three independent trials; error bars show SD. (C) Schematic of the donor chromosomes used to measure BIR efficiency showing the distance from the donor homology to the telomere. The TRP1-ys2 cassette and primers used to detect BIR are the same for all of the donor chromosomes.