Fig 2.

Regions of intersubspecific recombination were identified in five out of seven MLST gene regions plus rfbD using the introgression test. Recombinant introgression was identified by a significant increase in the ratio of polymorphic (Poly) to fixed (Fixed) sites (as defined in the text). The Fixed/Poly pairs progress from left to right along the sequence from 5′ to 3′. The data from recombinant portions are in boldface, together with the number of informative sites (in parentheses) and an estimate of length of the event (Rec. length). The “break position” (measured from the start position) is the midpoint between sites defining where the regions start and end. Our detection of intersubspecific recombination was compared to the patterns revealed using five other recombination tests (RDP, GeneConv [GC], MaxChi [MC], Chimaera [CH], and 3Seq [3S]; see the text). Each introgression detected is defined by the subspecific donor, the region detected, and the significance. The sequence data available were extended beyond that available from MLST using one representative of each ST (see Table 2).