TABLE 2.
Half-lives of cspA mRNA in different strains and conditions
| Strain | Allele | Half-life (s)a
|
||
|---|---|---|---|---|
| 42°C | 30°C | 15°C | ||
| MG1693 | Wild type | NDb | 47 | >600 |
| SK5665 | rne-1 | ND | 80 | >600 |
| KCB1008 | rne-131 | ND | 80 | >600 |
a
Cultures were grown in LB at 30°C and then shifted to 42°C for 20 min or to 15°C for 60 min prior to addition of rifampin. Samples were withdrawn at 45-s intervals (42°C and 30°C) or at 2.5-min intervals (15°C) and RNA extracted immediately. Half-lives were determined by primer extension using CSPA-PE1 (Table 1). The values given represent the averages of duplicate determinations.
b
ND, not detectable. The cspA mRNA extracted from cultures shifted to 42°C was badly smeared, even in the time zero sample (see the text).