Fig. 2.

Schematic analysis of the H. influenzae and P. multocida homologs of a hypothetical gene a. H. influenzae gene a contains three USSs, with position scores s =–0.2, s = 0.6, and s = 0.85. P. multocida gene a contains two USSs, with scores s = 0.6 and s =–0.8 (position 0.8 in the negative orientation). Plotting all these scores against each other gives the six spots shown in the graph. One comparison falls on the diagonal and is thus between putative homologs (comparison Ha-2:Pa-1), and the remaining five comparisons fall off the diagonal and are likely between nonhomologous USSs.