FIG 6.
(A) Reconstruction of the crm1 mutant leads to arrhythmic and rhythmic populations due to the presence (clones represented in gray) or absence (clones represented in magenta) of the RpaA-Q121 allele, respectively. (B) The conserved amino acid at position 121 of RpaA in cyanobacteria is arginine. An RpaA-L4-Q121 suppressor mutation restores LD fitness (C) and rhythmic gene expression (D). Dilution series of strains were grown in constant light (LL) or in 12-h light/dark cycles (12:12 LD) for 48 h to assess LD fitness. Bioluminescence from strains carrying a PkaiBC-luc reporter at NS2 was recorded as an assay for circadian rhythms of gene expression. LL, constant light after entrainment.