Moreover, biased phylogeny can also result from homologous recombination, which appears more frequently in symbiotic bacteria than expected based on their intracellular lifestyle and vertical transmission [26, 27]. The availability of the complete sequence of the Arsenophonus genome now provides the opportunity to perform a more accurate exploration of the evolutionary history and ecological spread of this pervasive

symbiotic bacterium on different host-taxonomical scales. Among the whiteflies, the Bemisia tabaci (Homoptera, Aleyrodidae) species complex has emerged as a focus of attention for several reasons, chief among them being the BMN-673 ongoing species radiation and the high prevalence of a wide diversity of LCZ696 solubility dmso endosymbiotic bacteria, selleckchem including several lineages of Arsenophonus [28]. The whitefly B. tabaci is a worldwide polyphagous pest of vegetables and ornamental crops, previously thought to be a unique species composed of several well-differentiated genetic groups or biotypes. Recently however, some of these groups have been recognized as true species, so that B. tabaci is now considered a complex of 24 cryptic species which barely interbreed and form different phylogenetic clades [29]. The biological data needed to draw clear boundaries among species and to identify the cause of such genetic differentiation are

still lacking. This phloem-feeding insect harbors a primary symbiont, Portiera aleyrodidarum, required for supplementing its specialized diet. B. tabaci also hosts up to six

vertically transmitted secondary symbionts, some of which are phylogenetically highly distant [23]. For each of these symbionts, the phenotypic consequences of infection in B. tabaci remain poorly identified, if at all [30]. Nevertheless, in other insect species, some of these bacteria are known to manipulate host reproduction, while others increase resistance to natural enemies [4, 10, 14, 31]. Moreover, the symbionts are thought to play a major role in the viral transmission capacities Oxalosuccinic acid of the pest [32, 33]. Interestingly, multiple bacterial infections are common in B. tabaci, and the endosymbiotic community is correlated with the B. tabaci genetic groups on different scales of differentiation [28, 34, 35]. This raises the question of these endosymbionts role in B. tabaci biology and species radiation. Within the 24 well-differentiated mtDNA groups recognized as true species by De Barro et al. [29] and that regroup all previously described biotypes, Arsenophonus has been found in AsiaII3 (ZHJ1 biotype), AsiaII7 (Cv biotype), Indian Ocean (Ms biotype), Mediterranean [Q and Africa Silver Leafing (ASL) biotypes which probably form true species] and the Sub-Saharan Africa species [Africa non-Silver Leafing (AnSL) biotype] [28, 34–38].