TABLE 1.
Strains used in this study
| Strain | Relevant genotype | Reference(s) or Source |
|---|---|---|
| LS20 | GAL lys5 ura3,52 leu2 his3 trp1 matΔ | 61 |
| NR85 | GAL ho HMLα leu2 mat::LEU2 hmr-Δ3 mal2 ura3-52 thr4 trp1 | 7 |
| CBY | GAL MATa ura3-52 trp1Δ1 lys2-801 his3Δ200 ade2-101 RAD52 | 8, 9 |
| gal MATα ura3-52 trp1Δ63 lys2-Δ202 his3Δ200 ade2-1 (oc) rad52::LEU2 | ||
| BY4741 | GAL MATa his3Δ1 leu2Δ met15Δ ura3Δ | K. Lewis |
| BY4742 | GAL MATα his3Δ1 leu2Δ lys2Δ ura3Δ | K. Lewis |
| CBY09 | GAL lys5 ura3 leu2 his3 trp1 matΔ hml::G418rhmr::TRP1a | This study |
| CBY10 | GAL lys5 ura3 leu2 his3 trp1 matΔ hml::G418rhmr::TRP1 sir2Δ::LEU2 | This study |
| CBY11 | GAL lys5 ura3 leu2 his3 trp1 matΔ hml::G418rhmr::TRP1 sir3Δ::LEU2 | This study |
| CBY12 | GAL lys5 ura3 leu2 his3 trp1 matΔ hml::G418rhmr::TRP1 sir4Δ::LEU2 | This study |
| CBY13 | GAL lys5 ura3 leu2 his3 trp1 matΔ hml::G418rhmr::TRP1 rad50Δ::LEU2 | This study |
| CBY14 | GAL lys5 ura3 leu2 his3 trp1 matΔ hml::G418rhmr::TRP1 sir4Δ::LEU2 rad50Δ::HygBr | This study |
| CBY15 | GAL lys5 ura3 leu2 his3 trp1 matΔ hml::G418rhmr::TRP1 rad9Δ::HygBr | This study |
| CBY16 | GAL lys5 ura3 leu2 his3 trp1 matΔ hml::G418rhmr::TRP1 rad9Δ::HygBrsir4Δ::LEU2 | This study |
| CBY17 | GAL lys5 ura3 leu2 his3 trp1 matΔ chr.III::[hmlΔ hmrΔ]b | This study |
| CBY18 | GAL lys5 ura3 leu2 his3 trp1 matΔ chr.III::[hmlΔ hmrΔ] sir2Δ::LEU2 | This study |
| CBY19 | GAL lys5 ura3 leu2 his3 trp1 matΔ chr.III::[hmlΔ hmrΔ] sir3Δ::LEU2 | This study |
| CBY20 | GAL lys5 ura3 leu2 his3 trp1 matΔ chr.III::[hmlΔ hmrΔ] sir4Δ::LEU2 | This study |
| CBY21 | GAL lys5 ura3 leu2 his3 trp1 matΔ chr.III::[hmlΔ hmrΔ] rad50Δ::HygBr | This study |
| CBY22 | GAL lys5 ura3 leu2 his3 trp1 matΔ chr.III::[hmlΔ hmrΔ] sir4Δ::LEU2 rad50Δ::HygBr | This study |
a
Precise deletions of the HO-cut sites were made within HML and HMR such that nonsilenced strains (sir−) retained the ability to express the regulatory proteins a1 and α2 and confer a nonmating, a1/α2 haploid phenotype. These strains have been designated HM+ in the text.
b
Chromosome III (chr.III) was circularized using a one-step targeted deletion of HML and HMR using G418r as the selectable marker (see Materials and Methods). These strains did not retain a1 or α2 and were unable to confer a nonmating haploid phenotype following the loss of silencing. They have been designated hm− in the text.