Wolbachia supergroup A in Enoplognatha latimana (Araneae: Theridiidae) in Poland as an example of possible horizontal transfer of bacteria

Abstract

Wolbachia (phylum Pseudomonadota, class Alfaproteobacteria, order Rickettsiales, family Ehrlichiaceae) is a maternally inherited bacterial symbiont infecting more than half of arthropod species worldwide and constituting an important force in the evolution, biology, and ecology of invertebrate hosts. Our study contributes to the limited knowledge regarding the presence of intracellular symbiotic bacteria in spiders. Specifically, we investigated the occurrence of Wolbachia infection in the spider species Enoplognatha latimana Hippa and Oksala, 1982 (Araneae: Theridiidae) using a sample collected in north-western Poland. To the best of our knowledge, this is the first report of Wolbachia infection in E. latimana. A phylogeny based on the sequence analysis of multiple genes, including 16S rRNA, coxA, fbpA, ftsZ, gatB, gltA, groEL, hcpA, and wsp revealed that Wolbachia from the spider represented supergroup A and was related to bacterial endosymbionts discovered in other spider hosts, as well as insects of the orders Diptera and Hymenoptera. A sequence unique for Wolbachia supergroup A was detected for the ftsZ gene. The sequences of Wolbachia housekeeping genes have been deposited in publicly available databases and are an important source of molecular data for comparative studies. The etiology of Wolbachia infection in E. latimana is discussed.

Figure 1

Maximum likelihood reconstruction of Wolbachia supergroup phylogeny based on concatenated sequence alignments of eight bacterial loci (16S rRNA, coxA, fbpA, ftsZ, gatB, gltA, groEL, hcpA) using MEGA 11 software. Strains are designated by their host names, except for outgroup bacteria. Capital letters indicate individual Wolbachia supergroups. Bar, substitutions per nucleotide. Bootstrap values based on 1000 replicates are shown on branches.

Figure 2

Alignment showing the unique 5′-GACTTCG-3′ sequence from the ftsZ gene of Wolbachia supergroup A from Enoplognatha latimana, Drosophila sturtevanti, Camponotus sayi, Ceutorhynchus assimilis, Ceutorhynchus obstrictus, Cyclosa confusa, Leucauge celebesiana, Leucauge subblanda, Lutzomyia stewarti, Metellina ornata, Mesida yini, Nedyus quadrimaculatus, and Wasmannia auropunctata.

Figure 3

Maximum likelihood reconstruction of Wolbachia supergroup phylogeny based on the wsp gene sequences using MEGA 11 software. Strains are designated by their host names. Wolbachia supergroups (A, B, and D) are indicated. Bar, substitutions per nucleotide. Bootstrap values based on 1000 replicates are shown on branches.

Figure 4

Median network reconstructed for Wolbachia supergroup A based on sequence polymorphism of the ftsZ genes. Conflicting phylogenetic signals (due to recombination and/or homoplasy) are represented as boxes or parallelograms in the network.