Table 1. Effect of qde-1 overexpression on the efficiency of silencing in al-1 and al-2 transformants in OQ1 and wild-type (WT) strains.
| Gene | Non-silenced (%) | Silencing in non-induced conditions (%) | Silencing in induced conditions (%) | Frequency of silencing excluding NS transformants with no al-1 transgene (%) | Total numbers analysed (n) |
|---|---|---|---|---|---|
| OQ1 strain | |||||
| al-1 | 22 | 21 | 78 | 92 | 1400 |
| al-2 | 23 | 23 | 73 | 90 | 780 |
| Wild-type strain | |||||
| al-1 | 78 | 22 | 22 | NA | 500 |
| al-2 | 81 | 19 | 20 | NA | 220 |
NS, non-silenced; NA, not available.
Colonies were either non-silenced (orange phenotype) or silenced (albino phenotype) irrespective of qde-1 overexpression, or inducibly silenced (albino phenotype) due to qde-1 overexpression induced by quinic acid. The frequency of silencing considers only those transformants that contain the al-1 transgene and was calculated by analysing non-silenced transformants for copy number. Two-thirds (66%) of the NS strains (eight out of 12 strains analysed) contained no copies of al-1 and are therefore ‘false negatives’, putting the actual level of silencing in conditions of qde-1 overexpression at ∼92%.