Table 5.
Dosage effects of BIR1 expression on the skp1-4 chromosome-loss phenotype
| Plasmid | Red colonies | Half-sectored colonies | Total colonies | Loss rate/ cell division* | Fold decrease† |
|---|---|---|---|---|---|
| YEp24 | 79 | 55 | 2,418 | 2.35 × 10−2 | 1.0 |
| YEp24-SKP1 | 0 | 1 | 3,577 | 2.80 × 10−4 | 84.1 |
| YEp24-CTF13 | 2 | 1 | 3,567 | 2.81 × 10−4 | 83.8 |
| YEp24-NDC10 | 66 | 36 | 2,356 | 1.57 × 10−2 | 1.5 |
| YEP24-CEP3 | 65 | 42 | 3,404 | 1.26 × 10−2 | 1.9 |
| YEp24-BIR1 | 0 | 1 | 6,933 | 1.44 × 10−4 | 163.0 |
| YEP24-BIR1 (N552) | 63 | 44 | 2,103 | 2.16 × 10−2 | 1.1 |
| YEP24-BIR1 (C405) | 4 | 4 | 2,349 | 1.71 × 10−3 | 13.8 |
| pRS316-SKP1 | 2 | 4 | 2,641 | 1.52 × 10−3 | 15.5 |
A high-copy plasmid, YEp24, carrying SKP1, CTF13, NDC10, CEP3, BIR1, 5′ 1.7-kb (N552), or 3′ 1.2-kb (C405) fragment of BIR1 was introduced into skp1-4 cells, and the colony sectoring assay was performed as described in Table 2, except that the plates were incubated at 25°C for 5 days. The plasmid pRS316 (CEN6, URA3) was used to obtain single gene dosage of SKP1.
*Loss rate/cell division = half-sectored colonies/(total colonies − red colonies).
† Fold decrease = loss rate/cell division of skp1-4 cells carrying YEp24 divided by loss rate/cell division of skp1-4 cells containing each of the indicated plasmids.