Comparison of phylogenetic relationships among Paulinella and free-living α-cyanobacteria inferred by rbcL and/or rDNA nucleotide sequence data. A. Unrooted analysis of codon positions 1+2 of the rbcL gene. B. Phylogeny of the rDNA operon, using more aligned positions as in Figure 1 (4317 vs. 4126 characters). C. Phylogeny inferred from concatenated rbcL and rDNA sequences. Tree topologies resulted from ML analyses using a GTR+I+Γ model; significance values shown as in Figure 1.