TABLE 5

Recombination frequencies at the CUP1, rDNA, and SUP4-o loci

CUP1a: 5-FOAR/total ×106rDNAb: 5-FOAR/total ×105SUP4-oc: 5-FOAR Ade CanR/total ×107
WT3.7 (± 0.96)d16 (± 3.8)2.1 (± 1.1)
pif1e88 (± 12)29 (± 6.6)16 (± 7.1)
rrm3100 (± 27)140 (± 66)4.3 (± 3.2)
sgs178 (± 6.1)130 (± 28)25 (± 6.1)
top3188 (± 43)220 (± 71)180 (± 47)
sgs1 top384 (± 26)40 (± 24)46 (± 6.4)
  • a 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).

  • b The rDNA locus contains 150–200 9.2-kb direct repeats in tandem as well as a replication fork barrier in each repeat.

  • c 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).

  • d 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.

  • e 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.