TABLE 5.
Recombination frequencies at the CUP1, rDNA, and SUP4-o loci
| CUP1a: 5-FOAR/total ×106 | rDNAb: 5-FOAR/total ×105 | SUP4-oc: 5-FOAR Ade− CanR/total ×107 | |
|---|---|---|---|
| WT | 3.7 (± 0.96)d | 16 (± 3.8) | 2.1 (± 1.1) |
| pif1e | 88 (± 12) | 29 (± 6.6) | 16 (± 7.1) |
| rrm3 | 100 (± 27) | 140 (± 66) | 4.3 (± 3.2) |
| sgs1 | 78 (± 6.1) | 130 (± 28) | 25 (± 6.1) |
| top3 | 188 (± 43) | 220 (± 71) | 180 (± 47) |
| sgs1 top3 | 84 (± 26) | 40 (± 24) | 46 (± 6.4) |
The CUP1 locus consists of six to seven 2.0-kb direct repeats in the assay strain (W1588-4C background) as determined by gel blot analysis and phosphorimager quantitation (data not shown).
The rDNA locus contains 150–200 9.2-kb direct repeats in tandem as well as a replication fork barrier in each repeat.
The SUP4-o locus contains five ∼330-bp δ repeats in both direct and inverse orientations as well as replication pause sites (Rothstein et al. 1987).
See materials and methods for details of how each assay was performed. Each value represents the deletion frequency between direct repeats at the indicated locus and is the average of a minimum of five experiments in which independent segregants were used. Standard deviations are given in parentheses.
Null mutant strains were used except in the case of the SUP4-o assay in which case the pif1-m2 strain was used for technical reasons (see materials and methods). Strains used in this analysis were constructed by crossing the appropriate mutation into the appropriate assay strain: W3831-1B (CUP1 assay), W3480-4C (rDNA assay), or W1868-8B (SUP4-o assay). The sgs1 and top3 deletions were derived from a W1958 segregant. The pif1 deletion was derived from strain J1129. The pif1-m2 mutation was derived from strain W3972-7C. The rrm3 deletion was derived from strain J1132.