FIG. 2.

Overview of vlsE antigenic switching in B. burgdorferi. Variant-specific segments act as a source of DNA for nonreciprocal recombination events with the vlsE expression locus. Through this process, segments of the variable region are replaced by sections of varied length and location from the donor sequences. In the example shown, three sequential gene-conversion events (dashed lines) occur within each expression site through recombination with the colored donor sections to generate a new expression site sequence with a mosaic structure. p, vlsE promoter (reprinted with permission from John Wiley & Sons, Inc., Copyright 2009).⁴