Effects of the Cryptochrome CryB from Rhodobacter sphaeroides on Global Gene Expression in the Dark or Blue Light or in the Presence of Singlet Oxygen
Figure 5
Northern blot analysis of the small RNA RSs0680a under different conditions.
RSs0680a expression is increased in 2.4.1ΔcryB under singlet oxygen (A) but not under blue light conditions (B) or microareobic growth (C). Experiments were performed as described and 12 µg of total RNA seperated on 10% polyacrylamid gels containing 7 M urea. 5′-labeled oligodeoxynucleotide probes were used for detection of RSs0680a and 5S rRNA, which served as internal loading control. RSs0680a expression is induced approximately 2–3 times after 20 minutes of 1O2 exposure in Rhodobacter sphaeroides wild type (WT) and the cryB deletion mutant compared to unstressed cells (0 min). The levels of the sRNA after 0 and 20 minutes 1O2 treatment, respectively are increased approximately 5–6 times in 2.4.1ΔcryB compared to WT. No significant differences in expression can be detected under blue light treatment. Oxygen shift experiments show that RSs0680a is more abundant in 2.4.1ΔcryB under aerobic conditions (time point 0 min). After shifting cultures to non-stressed, microaerobic conditions no significant difference in RSs0680a expression is detected for both strains.