Table 1.
Effect of homoeologous chromosomes on ectopic recombination
| Location (chromosome–locus)
|
f(ARG4) × 103* | Relative to nonhybrid | |
|---|---|---|---|
| arg4-nsp | arg4-bgl | ||
| Nonhybrid strains | |||
| III–MAT | V–ura3 | 0.25 ± 0.04 | |
| V–ura3 | III–MAT | 0.40 ± 0.10 | |
| VIII–put2 | V–ura3 | 0.15 ± 0.02 | |
| V–ura3 | VIII–put2 | 0.15 ± 0.02 | |
| VIII–ppx1 | V–ura3 | 0.36 ± 0.04 | |
| V–ura3 | VIII–ppx1 | 0.32 ± 0.01 | |
| III–MAT | VIII–put2 | 0.31 ± 0.08 | |
| VIII–put2 | III–MAT | 0.65 ± 0.1 | |
| Homoeologous chromosome V | |||
| III–MAT | V–ura3 | 0.82 ± 0.06 | 3.3 |
| V–ura3 | III–MAT | 1.1 ± 0.17 | 2.8 |
| VIII–put2 | V–ura3 | 0.98 ± 0.1 | 6.5 |
| V–ura3 | VIII–put2 | 0.72 ± 0.17 | 4.8 |
| VIII–ppx1 | V–ura3 | 1.9 ± 0.36 | 5.3 |
| V–ura3 | VIII–ppx1 | 1.7 ± 0.19 | 5.3 |
| III–MAT | VIII–put2 | 0.34 ± 0.06 | 1.1 |
| VIII–put2 | III–MAT | 0.67 ± 0.06 | 1.0 |
| Homoeologous chromosomes V and III | |||
| III–MAT | V–ura3 | 1.70 ± 0.05 | 6.8 |
| V–ura3 | VIII–put2 | 0.81 ± 0.11 | 5.4 |
| III–MAT | VIII–put2 | 0.69 ± 0.09 | 2.2 |
arg4 mutant alleles were present on hemizygous copies of a URA3-arg4 insert (see Fig. 1) at MAT (chromosome III), at URA3 (chromosome V), at PUT2 (chromosome VIII), or at PPX1 (chromosome VIII). Strains with homoeologous chromosomes V or III contain one chromosome each from S. cerevisiae and S. carlsbergensis. The arg4 insert was always present on the S. cerevisiae chromosome.
*
ARG4 spores/total viable spores, mean ± standard deviation.