Clustering of variable genes and regions detected by tiling microarray of 31 S. suis strains.

(A) Clustering of regions of difference (RDs) and S. suis strains based on the presence or absence of RDs in the 31 test strains. For each individual strain, the presence of a RD is represented by a black box, whereas the absence of a RD corresponds to a cyan box. The dendrogram constructed by average linkage hierarchical cluster analysis shows the relationships of the 31 strains. The strain names and sequence types are presented on the right side. RD numbers are given at the top and red text indicates high pathogenicity associated RDs. (B) Clustering based on the presence or absence of singular variable genes (SVGs). Color coding is the same as in (A).