Phylogeny of the arthropod endosymbiont Wolbachia based on the wsp gene

Bacteria of the genus Wolbachia (Rickettsiae) are widespread in arthropods and can induce cytoplasmic incompatibility (CI), thelytoky (T) or feminizat ion (F) in their host. Recent research on the wsp gene of mainly CI inducin g Wolbachia has shown that this gene evolves at a much faster rate than pre viously sequenced genes such as 16S or ftsZ. As a result this gene appears to be very useful in subdividing the Wolbachia and twelve groups have been distinguished to date. Here we extend the Wolbachia wsp data set with fifte en T-Wolbachia, one F-Wolbachia and three other Cl-Wolbachia strains. The r esults showed: (i) the addition of seven groups; (ii) no relation between h ost phenotype and Wolbachia phylogenetic position; and (iii) possible horiz ontal Wolbachia transfer between the moth Ephestia kuehniella and its paras itoid Trichogramma spp.