FIG. 3.

Linear distribution of 182 polymorphic nucleotide positions in a multiple alignment of 16S rRNA sequences representing five genera (Agrobacterium, Brucella, Mesorhizobium, Rhizobium, and Sinorhizobium) within the order Rhizobiales. Each vertical line represents a deviation from the consensus sequence. The locations of hypervariable expansion segments (V1 through V10) described by Raué et al. (15) are shown at the bottom. Brackets define endpoints of segments that were identified by the Stephens test as containing nonrandom clusters of partition-specific nucleotide sequences. Shaded segments indicate runs of sequence similarity that were identified by Sawyer's Geneconv method.