TABLE 4.
[URE3] induction by overexpression of PFD in S. uvarum Su[ure0] and S. paradoxus Sp[ure0] strains
| Plasmid | [URE3] frequency | Induction fold above the spontaneous frequency |
|---|---|---|
| A. In S. uvarum | ||
| Vector | 2.1 × 10−6 | |
| PFDSc | 2.7 × 10−5 | 13 |
| PFDSp | 5.2 × 10−5 | 25 |
| PFDSu | 6.0 × 10−6 | 3 |
| PFDKl | 1.9 × 10−6 | 1 |
| Plasmid | [Ade+] frequency | [URE3] frequency |
| B. In S. paradoxus | ||
| Vector | 3.11 × 10−5 | |
| PFDSc | 2.40 × 10−5 | <10−7 |
| PFDSp | 4.05 × 10−5 | <10−7 |
| PFDSu | 1.55 × 10−5 | <10−7 |
| PFDKl | 1.44 × 10−5 | <10−7 |
Strains were transformed with plasmids allowing the overexpression of the different PFD(Sc,Sp,Su,Kl) from a galactose-inducible promoter (pYe2L-URE2(Sc,Sp,Su,Kl)ΔC). Some clones of transformed strains were grown on raffinose/galactose minimal medium for 72 hr to induce overexpression. Then cells were plated onto glucose SD medium. After 5 days of growth, [ADE+] clones were collected and their [URE3] state was then monitored as described in the results. The [URE3] state of 200 [Ade+] clones was then monitored as described in the results. It should be noted that upon overexpression with PFDSc, PFDSp, and PFDSu, in S. uvarum all the [Ade+] clones obtained were [URE3].