TABLE 1.
S. pombe strains used in this study
| Brief genotype | Genotypea | Description | Source |
|---|---|---|---|
| Wild type | Wild type | Normal cell cycle; normal DNA damage and replication checkpoints | Our stock |
| cdc2-1w | cdc2-1w | Constitutively active Cdc2 refractory to Wee1-mediated Y15 phosphorylation | Our stock |
| cdc2-3w | cdc2-3w | Cdc2 activated by Cdc25-independent dephosphorylation of Y15 | Our stock |
| Δwee1 | ura4-D18 wee1::ura4+ | No expression of Wee1, a negative regulator of Cdc2 | Our stock |
| wee1-50 | wee1-50 | Wee1 ts mutant functional at 23°C, but not at 32.5°C | Our stock |
| Δnim1 | ura4-D18 nim1::ura4+ | No expression of Nim1, a negative regulator of Wee1 | Our stock |
| wee1-50 Δmik1 | ura4-294 wee1-50 mik1::ura4+ | No expression of Mik1, the twin kinase of Wee1, with the wee1-50 mutation | Our stock |
| cdc2-3w Δcdc25 | cdc2-3w ura4-D18 cdc25::ura4+ | No expression of Cdc25, a positive regulator of Cdc2, with the cdc2-3w mutation | P. Nurse |
| rad1-1 | rad1-1 | Nonfunctional Rad1, a transducer for DNA damage and replication checkpoints | Our stock |
| Δchk1 | ura4-D18 chk1::ura4+ | No expression of Chk1, a transducer for DNA damage and replication checkpoints | Our stock |
| Δrad24 | ura4-D18 rad24::ura4+ | No expression of Rad24 involved in cell cycle control and DNA damage checkpoint | Our stock |
| Δcds1 | ura4-D18 cds1::ura4+ | No expression of Cds1, a transducer for DNA replication checkpoint | Our stock |
| Δppa1 | ura4-D18 ppa1::ura4+ | No expression of Ppa1, a catalytic subunit of PP2A | M. Yanagida |
| Δppa2 | ura4-D18 ppa2::ura4+ | No expression of Ppa2, a catalytic subunit of another isozyme of PP2A | M. Yanagida |
a
The genetic background common to all of the strains (h− leu1-32) is omitted.