Table 2.

Effects of oxygen and light on puf mRNA levels, pufQ- and pufL-lacZ expression, and photopigment synthesisa

OrganismGrowth conditionbmRNA contentcpufQ-lacZe pufL-lacZf BChlg
0.5 kb3.5 (2.7) kbd
R. sulfidophilum HL-ANA100100100100100
LL-ANA127114109135128
DK-AER8685333584
HL-AER39212751
R. capsulatus HL-ANA100100 NTh NT100
LL-ANA136115NTNT130
DK-AER3033NTNT<1
HL-AER2021NTNT<1
  • a Indicated as percentages of the values under anaerobic high-intensity-light conditions (set as 100).

  • b HL-ANA, anaerobic high-intensity light (100 W/m2); LL-ANA, anaerobic low-intensity light (3 W/m2); DK-AER, aerobic dark; HL-AER, aerobic high-intensity light (100 W/m2).

  • c The relative amounts of mRNA were measured by Northern hybridization and quantified by the photoimaging system (Fig.1c).

  • d 3.5 kb, R. sulfidophilum puf mRNA; 2.7 kb, R. capsulatus puf mRNA (Fig. 1c).

  • e The relative activities of thepufQ-lacZ transcriptional fusion were calculated based on the β-galactosidase activity of pPS100 in R. sulfidophilumin Fig. 4. Results are based on the averages of at least three independent assays, and the uncertainty limits in single measurements are within 20%.

  • f The relative activities of thepufL-lacZ transcriptional fusion were calculated based on the β-galactosidase activity of pPS001 in R. sulfidophilumin Fig. 4. Results are based on the averages of at least three independent assays, and the uncertainty limits in single measurements are within 15%.

  • g Relative BChl contents in membrane preparations were determined as described in Materials and Methods. Results are based on at least three independent assays, with single measurements varying less than 5% from that value.

  • h NT, not tested.