Classification of Wolbachia (Alphaproteobacteria, Rickettsiales): No evidence for a distinct supergroup in cave spiders

Abstract

Wolbachia are intracellular, inherited Alphaproteobacteria present in a large proportion of arthropod species and in filarial nematodes. Wolbachia-host interactions are many-faceted and include, but are not limited to reproductive manipulations (Werren et al. 2008), nutritional mutualism (Nikoh et al. 2014), and protection from pathogens (Hedges et al. 2008, Teixeira et al. 2008). Although there is just a single Wolbachia species described, the genus is highly diverse with regard to its distribution, phenotypes induced in the host, and genomic architecture. The generally accepted classification scheme currently in use differentiates among genetically distinct, monophyletic lineages named 9supergroups9 (Lindsey et al. 2016). To date, 16 of these Wolbachia lineages that - based on multiple genetic markers - are clearly distinct from another were described (supergroups A-F and H-Q, Glowska et al. 2015). In a recent study, Wang et al. (2016) reported the discovery of a novel, 17th Wolbachia supergroup (9R9) from cave spiders (Telema ssp.). The authors base this conclusion on phylogenetic analyses of sequences from three protein coding genes (ftsZ, coxA, groEL) and the 16S rRNA gene. Here, I re-analyse these data and show that Wolbachia from Telema spiders clusters with supergroup A strains and thus, the creation of a novel Wolbachia supergroup for these strains is without justification.