Association among species by physico-chemical characteristics of ortholog products. A, polarity is shown as example. The panel shows 705 syntenic ortholog products per species. Letters at the top: At, A. tumefaciens; Re, R. etli; Sm, S. meliloti; Bm, B. melitensis; and Ml, M. loti. Lines at left denote clusters of orthologs with similar profile in the five species (ten were selected and analyzed in the text). B, comparison of two R. etli strains with polarity. The panel shows 705 syntenic ortholog products per strain. Letters at the top: Re, R. etli strain CFN42; CIAT, R. etli strain CIAT652. Clustering was performed with MeV TM4 . Scales for normalized values (green for negative values, white for zero, and red for positive).