The same configuration of Ty elements promotes different types and frequencies of rearrangements in different yeast strains.
We examined Ty-mediated genomic rearrangements in three related mitotically dividing haploid yeast strains having the same configuration of Ty elements in the CYC1-sup4 interval of chromosome X. Surprisingly, quite different types and frequencies of rearrangements were found in the three strains. In one strain we found only Ty-mediated deletions, which occurred with a frequency of about 1 X 10(-6). Another strain yielded similar deletions, but approximately one-third of these were accompanied by adjacent Ty-mediated inversions. A third strain was found to have an extremely high rate of inversion/reinversion between two of the three Ty elements. This rate was conservatively estimated to be 1.4 +/- 0.2 X 10(-2) per cell per generation, which is at least 2 orders of magnitude higher than previously reported values for Ty-mediated rearrangements. These data provide evidence that local regions of the genome can, in some cases, be much more fluid than had been previously believed.
Picologlou
S
S
Department of Biological Sciences, University of Illinois, Chicago 60680.
Dicig
M E
ME
Kovarik
P
P
Liebman
S W
SW
D002872:Chromosome Deletion; D003433:Crosses, Genetic; D004262:DNA Restriction Enzymes; D004251:DNA Transposable Elements; D005800:Genes, Fungal; D009693:Nucleic Acid Hybridization; D011336:Probability; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D013045:Species Specificity
D004251:DNA Transposable Elements; D004262:DNA Restriction Enzymes