Figure 3.

Schematic representation of the hypothetical evolutionary acquisition of the T3SS-related gene cluster in V. parahaemolyticus, V. cholerae and V. mimicus. Lineage is based on the presence of each of the determinants, for example, tdh, trh, CTX and T3SS2. The shaded ellipses show the T3SS-related gene clusters, bold lines represent the evolutionary process, and circles represent the strains of V. parahaemolyticus, V. cholerae and V. mimicus, while shaded circles indicate that the strains possess T3SSα or T3SSβ. Broken lines indicate that the T3SS gene clusters or CTX have been acquired by horizontal gene transfer while the organisms were evolving.