Figure 5. Progressive recombination in vlsE variant clones.

(A) Schematic representation of possible recombination events for three clones derived from a single day 10 bladder culture. The shaded gray boxes indicate the variable regions (VR). Colored bars represent the maximum possible length of DNA involved in a putative recombination event for each vls silent cassette. Dark colored blocks within the colored bars represent observed sequence changes between vlsE and the variant sequence that are present in the selected silent cassette. (B) Postulated sequence of recombination events leading to the three clones.