Phylogenetic analysis based on the 16S rDNA, gltA, gatB, and hcpA gene sequences of Wolbachia sp. from the novel host Ceratozetes thienemanni (Acari: Oribatida).

We determined the occurrence of intracellular endosymbionts (Wolbachia sp., Cardinium sp., Arsenophonus sp., Rickettsia sp., Spiroplasma sp., Hamiltonella sp., Flavobacterium, and microsporidia) in oribatid mites (Acari: Oribatida) with the use of PCR technique. For the first time we looked for and detected Wolbachia sp. in parthenogenetic oribatid mite Ceratozetes thienemanni Willmann, 1943. The 16S rDNA, gatB, hcpA, and gltA sequences of Wolbachia sp. in C. thienemanni showed the highest similarity (≥ 90%) to the genes of Wolbachia sp. from springtails Collembola and oribatid mite Gustavia microcephala. We found the unique sequence 5'-GGGGTAATGGCC-3' in 16S rDNA of Wolbachia sp. from C. thienemanni and collembolan representing group E. The phylogeny of Wolbachia sp. based on the analysis of single genes as well as concatenated alignments of four bacterial loci showed that the bacteria from C. thienemanni belonged to Wolbachia sp. group E, like the endosymbionts from springtail hosts and G. microcephala. Considering coexisting of representatives of Oribatida and Collembola in the same soil habitat and similar food, it is possible that the source of Wolbachia sp. infection was the same. Residues of dead invertebrates could be in organic matter of their soil food, so the scenario of infection transferred by eating of remains of soil cohabitates is also possible. It could explain the similarity and relationship of the Wolbachia sp. in these two arthropod groups. Oribatid mite C. thienemanni is a parthenogenetic mite which is a unique feature in the genus Ceratozetes. Moreover, this species, within the entire genus Ceratozetes, is characterized by the most northerly distribution. It is difficult to determine either it is parthenogenesis or the presence of endosymbionts that are in some way responsible for this kind of evolutionary success. Maybe we are dealing here with a kind of synergy of both factors?