FIG. 1.

DSB-induced LOH results from large translocations in a wild-type background. (A) Schematic of the Ch¹⁶-MGH strain. Ch¹⁶-MGH, ChIII, centromeric regions (ovals), complementary heteroalleles (ade6-M216 and ade6-M210) (white), ade5⁺ (vertical stripes), and a MATa site (black) with an adjacent kanMX6 resistance marker (gray) are shown, as previously described (45). The his3⁺ marker (dark gray) was inserted ∼25 kb downstream of the MATa site. Derepression of pREP81X-HO (not shown) generates a DSB at the MATa target site (scissors). In Ch¹⁶-MHH, kanMX6 is replaced by hph. (B) PFGE analysis of chromosomal DNA from a wild-type S. pombe strain (lane 1), an “uncut” wild-type strain (TH1436) encoding Ch¹⁶-MGH (Ch¹⁶-MGH; lane 2), a strain encoding Ch¹⁶-MGH repaired by gene conversion following DSB induction (ade⁺ G418^s his⁺; lane 3), and three individually isolated ade⁺ G418^s his⁻ colonies following DSB induction (lanes 4, 5, and 6). (C and D) Southern blot analysis of the PFGE shown in panel B probed with rad21 (C) and ade5 (D). (E) High-resolution PFGE analysis of colonies shown in panel B.