Playing Peekaboo with a Master Manipulator: Metagenetic Detection and Phylogenetic Analysis of Wolbachia Supergroups in Freshwater Invertebrates

The infamous master manipulators-intracellular bacteria of the genus Wolbachia-infect a broad range of phylogenetically diverse invertebrate hosts in terrestrial ecosystems. Wolbachia has an important impact on the ecology and evolution of their host with documented effects including induced parthenogenesis, male killing, feminization, and cytoplasmic incompatibility. Nonetheless, data on Wolbachia infections in non-terrestrial invertebrates are scarce. Sampling bias and methodological limitations are some of the reasons limiting the detection of these bacteria in aquatic organisms. In this study, we present a new metagenetic method for detecting the co-occurrence of different Wolbachia strains in freshwater invertebrates host species, i.e., freshwater Arthropoda (Crustacea), Mollusca (Bivalvia), and water bears (Tardigrada) by applying NGS primers designed by us and a Python script that allows the identification of Wolbachia target sequences from the microbiome communities. We also compare the results obtained using the commonly applied NGS primers and the Sanger sequencing approach. Finally, we describe three supergroups of Wolbachia: (i) a new supergroup V identified in Crustacea and Bivalvia hosts; (ii) supergroup A identified in Crustacea, Bivalvia, and Eutardigrada hosts, and (iii) supergroup E infection in the Crustacea host microbiome community.

Automated summary

In this study, a new metagenetic method was developed for detecting the co-occurrence of different Wolbachia strains in freshwater invertebrate host species. Three supergroups of Wolbachia were identified: a new supergroup V in Crustacea and Bivalvia hosts, supergroup A in Crustacea, Bivalvia, and Eutardigrada hosts, and supergroup E infection in the Crustacea host microbiome community.