Presence and distribution of the endosymbiont Wolbachia among Solenopsis spp. (Hymenoptera: Formicidae) from Brazil and its evolutionary history

Abstract

Wolbachia are intracellular bacteria that commonly infect arthropods. Its prevalence among ants of the genus Solenopsis is high. In the present study, the presence and distribution of these endosymbionts was examined among populations of Solenopsis spp. from Brazil. A phylogenetic analysis based on the wsp gene was conducted to infer the evolutionary history of Wolbachia infections within the populations surveyed. A high frequency of Wolbachia bacteria was observed among the genus Solenopsis, 51% of the colonies examined were infected. Incidence was higher in populations from southern Brazil. However, little genetic variability was found among different Wolbachia strains within supergroups A and B. Our findings also suggest that horizontal transmission events can occur through the social parasite S. daguerrei.

Intracellular Symbiotic Bacteria of Camponotus textor, Forel (Hymenoptera, Formicidae)

“…Camponotus textor had a high rate of Wolbachia infection compared to Solenopsis spp. from the same region [25], suggesting that the bacteria may be at or near fixation, as suggested by Wenseleers et al [42] in F. truncorum, Fabricius. However, the ST and the wsp gene did not vary among different colonies, suggesting that the Wolbachia infection may have occurred a long time ago in the common ancestor of the populations.…”

“…However, an additional question may be raised: why would these multiple strains not be quickly lost due to genetic drift? Genetic drift does not prevent the co-occurrence of multiple strains of Wolbachia within the same individual [25,26,49,50], and we believe the same could be the case for Blochmannia, explaining its diversity. If functional divergence has occurred, akin to the recent diversification of symbionts in cicadas reported by Campbell et al [51], more studies will be needed to understand the diversity of Blochmannia in Camponotus sp.…”

“…Other few studies involving ants and endosymbionts from the Neotropical region have already shown how diverse these associations are [25,26]. Since the descriptions of primary and secondary symbionts in Camponotus are based on species from the Northern Hemisphere, the goal of this study was to investigate the presence, frequency of occurrence, and strain diversity of Wolbachia and Blochmannia in C. textor colonies, which are ants exclusively Neotropical, and evaluate the diversity of these endosymbionts.…”

Analysis of the Hypervariable Regions (HVRs) of the wsp Gene of Wolbachia from Solenopsis invicta Ants in Southeastern Brazil

“…Ant species identification was conducted based on the cytochrome oxidase I (COI) gene using the Barcode method [14]- [17]. The mtDNA sequences (approximately 920-bp region of the cytochrome oxidase I) were ana- lyzed with Bioedit software [18] and compared with sequences in the National Center for Biotechnology Information (NCBI) database via BLAST searches (http://blast.ncbi.nlm.nih.gov/Blast.cgi).…”

“…The GTR+G model was selected and the Markov chain was run for 1,000,000 generations sampled every 100 generations. The first 10% of the trees were excluded, and the subsequent probability values were calculated using the remaining trees assuming a mid point rooting [17]. For comparison purposes, we included in the analyses Wolbachia sequences previously detected in S. invicta and provided by Dr. David Dewayne Shoemaker from the Center for Medical Agricultural and Veterinary Entomology, USDA-ARS, USA.…”