Fig. 2.

Putative virulence genes revealed by comparative genome hybridization analysis. A total 156 genes diverged or absent in at least one of the three avirulent isolates were compared across the virulent isolates by using hierarchical clustering. Eighty genes that show little or no variation in virulent isolates were found in three different locations in the cluster, denoted as groups 1–3. Putative virulence genes and the genes shown to be highly expressed in hamster spleen (see Table 9) are highlighted. B. mallei isolates used for this study, microarray hybridization pairs, and a graph of gene distribution by chromosomes are also shown.