Figure 3.

Novel restriction fragments detected in the 225-kb amplicon by the 2.6-kb EcoRI fragment. (A) Sheared genomic DNA from the wild-type (Wt) strain and from a strain carrying a 225-kb amplicon (Amp) was digested with EcoRI, SnaBI, HaeIII, or NcoI, and the fragments were separated by gel electrophoresis. The transfers were hybridized with labeled PCR products from within the 2.6-kb EcoRI fragment of cosmid 79. Numbers indicate the sizes of the fragments in kilobases. Boxed numbers indicate novel fragments, which were detected only in strains containing the 225-kb amplicon. (B) Restriction map of the novel fragment. Gen, map of the genomic region. Amp, map of the amplicon, deduced from the sizes of the novel fragments. The map of chromosome I is deduced from sequence data (the S. pombe genome project) and restriction data (our unpublished results). The sizes of the novel fragments are consistent with a palindromic amplicon with a novel joint immediately after the inverted repeat. The triangles represent the inverted repeats. The black ovals represent unique sequences found only telomere-proximal to the inverted repeats in wild-type DNA. E, EcoRI; Sn, SnaBI; H, HaeIII; N, NcoI