TABLE 1

Genome alterations in subcultured tel1 mec-21 haploid strains derived from diploids MV58 and MV59

Strain nameGenome alterations
MV58-20a#1Disomy for VIII. Two copies of III, one ∼100 kb smaller than wild type and one ∼100 kb larger (products of unequal crossing over between MAT and HMR). No Y′ amplification.
MV58-20a#2Disomy for VIII. Two copies of III, one wild-type chromosome and one with a deletion between MAT and HMR. Y′ amplification.
MV58-20a#3Disomy for VIII. Interstitial 35-kb duplication of VII [breakpoints near unannotated Ty elements (A. Gabriel, personal communication) located at YGRWδ19 and YGRWδ21]. Two copies of III, one wild-type chromosome and one isochromosome with duplication of sequences between LAHS and left telomere, and deletion of sequences distal to FS1. No Y′ amplification.
MV58-20a#4Disomy for VIII. Two copies of III, one normal copy and one isochromosome with duplication of sequences between the LAHS and the left telomere, and deletion of sequences distal to YCRCδ6. Y′ amplification.
MV58-20a#5Disomy for VIII (normal size). Two copies of III, one normal copy and one isochromosome with duplication between the LAHS and the left telomere, and deletion of sequences distal to FS2. No Y′ amplification.
MV58-20a#6Intrachromosomal duplication on chromosome IV between two pairs of Ty elements (YDRWTy2-2/YDRCTy1-2 and YDRWTy2-3/YDRCTy1-3). Three chromosomes with sequences from IIIL: (1) normal III, (2) isochromosome with duplication between the LAHS and the left telomere and deletion of sequences distal to YCRCδ6, and (3) translocation between YHRCTy1-1 on VIII and Ty at LAHS on III. No Y′ amplification.
MV58-20a#7Disomy for VIII. Translocation between III and X with breakpoint on III near the LAHS and breakpoint on X near YJLCδ4, which maps near an unannotated Ty (A. Gabriel, personal communication). Two other uncharacterized chromosome rearrangements involving chromosome III. Y′ amplification.
MV59-6a#1Disomy for VIII. Two copies of III, one isochromosome resulting from recombination between YCLCδ6 and the LAHS and one circular chromosome resulting from recombination between HML and HMR. Y′ amplification.
MV59-6a#2Disomy for VIII. Two copies of III, one normal and one with the Hawthorne deletion (loss of region between MAT and HMR). Y′ amplification.
MV59-6a#3Disomy for VIII. Two copies of III, one normal and one with the Hawthorne deletion (loss of region between MAT and HMR). Y′ amplification.
MV59-6a#4Disomy for VIII. Y′ amplification.
MV59-6a#5Disomy for 640-kb III–VIII translocation with breakpoints near LAHS on III and YHRCTy1-1: 440-kb derivative of III with duplication of region between the LAHS and FS1. Y′ amplification.
MV59-6a#6No disomy for VIII, but chromosome is ∼60 kb larger than the wild type; the origin of the extra DNA is not known. Disomy for III. Y′ amplification.
MV59-6a#7No disomy for VIII and VIII of normal size. III is ∼100 kb larger than the normal chromosome as a consequence of an unequal crossover, duplicating the region between MAT and HMR. Y′ amplification.
MV59-16c#1Disomy for VIII: 250-kb III–XII translocation with breakpoints at the LAHS and near YLRCsigma1, which maps at an unannotated Ty (A. Gabriel, personal communication). Interstitial 35-kb duplication of VII (same breakpoints as MV58-20a#3). Y′ amplification.
MV59-16c#2Disomy for VIII. One VIII of normal size (565 kb) and one ∼640 kb (VIII–XV translocation between YHRCTy1-1 and YOLWTy1-1); 250-kb III–XII translocation with same breakpoints as MV59-16c#1. No Y′ amplification.
MV59-16c#3Disomy for VIII. One VIII of normal size (565 kb) and one ∼640 kb (VIII–XV translocation between YHRCTy1-1 and YOLWTy1-1). Two copies of III, one normal III and one isochromosome resulting from recombination between YCLCδ6 and the 5′ δ of Ty1 at the LAHS. Interstitial 35-kb duplication of VII (same breakpoints as MV58-20a#3). Y′ amplification.
MV59-16c#4Disomy for I and VIII. Two copies of III, one normal III and one isochromosome resulting from recombination between YCLCδ6 and the 5′ δ of Ty1 at the LAHS. Y′ amplification.
MV59-16c#5Uncharacterized alteration duplicating the leftmost 280 kb of VIII. Extensive Y′ amplification.
MV59-16c#6Disomy for chromosome VIII. Both VIII and III hybridized to regions extending ∼50 kb beyond their normal size, probably the result of extensive Y′ amplification.
MV59-16c#7Disomy for chromosome VIII. Interstitial 35-kb duplication of VII (same breakpoints as MV58-20a#3). No Y′ amplification.
  • These haploid strains were derived from sporulation of diploids heterozygous for the tel1 and mec1-21 mutations, as described in the text. These strains are isogenic with W303a (Thomas and Rothstein 1989). The strains were subcultured 10 times before analysis. Prior to subcloning, none of the strains had chromosome rearrangements, although all were disomic for chromosome VIII.