FIG. 2.

Northern blot analysis of total RNA from the wild-type strain (WT; lanes 1 and 2), the sll0030 insertional mutant (MR1; lanes 3 and 4), the sll1594 insertional mutant (MR2; lanes 5 and 6), and the sll0030 sll1594 double mutant (R12; lanes 7 and 8) of Synechocystis sp. strain PCC 6803, showing the effects of CO₂ conditions on expression of the cmp and rbc operons. Cells were grown under high CO₂ conditions (2% CO₂ in air) and transferred to low CO₂ conditions (0.005% CO₂ in air); total RNA samples (10 μg per lane) were extracted from the cells before (lanes 1, 3, 5, and 7) and 90 min after (lanes 2, 4, 6, and 8) the transfer and analyzed, using probes specific to cmpA-cmpB-slr0042 (A) and rbcL (B). Arrowheads indicate calculated sizes (in kilobases) of the full-length mRNA of the cmp operon (A) and the rbc operon (B).