Potential gene transfers with members of the Rickettsiales order. The bayesian trees for each orthologous gene (ID 387, 388, 390, and 134) and their 10 best BLAST hits show the clustering of Chlamydiales and Legionellales with members of the Rickettsiales order. The retrieval of BLAST hits was restricted to one per bacterial genus for (A), (B), and (D) but not for (C). Sequences retrieved using L. drancourtii or P. acanthamoebae as the query in a BLAST homology search are tagged with an LLAP or PAH prefix, respectively. Sequences belonging to the best BLAST hits for both orthologues harbor both prefixes.