title: Reevaluating the infection status by the Wolbachia endosymbiont in Drosophila Neotropical species from the willistoni subgroup.
abstract: Infections by the endosymbiotic bacterium Wolbachia developed a rapid global expansion within Old World Drosophila species, ultimately infecting also Neotropical species. In this sense, screenings are necessary to characterize new variants of Wolbachia or new hosts, and also in order to map the dynamics of already known infections. In this paper, we performed a double screening approach that combined Dot-blot and PCR techniques in order to reevaluate the infection status by Wolbachia in species from the willistoni subgroup of Drosophila. Genomic DNA from isofemale lines descendent from females collected in the Amazonian Rainforest (n=91) were submitted to Dot-blot, and were positive for Wolbachia, producing a gradient of hybridization signals, suggesting different infection levels, which was further confirmed through quantitative PCR. Samples with a strong signal in the Dot-blot easily amplified in the wsp-PCR, unlike most of the samples with a medium to weak signal. It was possible to molecularly characterize three Drosophila equinoxialis isofemale lines that were found to be infected in a low density by a wMel-like Wolbachia strain, which was also verified in a laboratory line of Drosophila paulistorum Amazonian. We also found Drosophila tropicalis to be infected with the wAu strain and a Drosophila paulistorum Andean-Brazilian semispecies laboratory line to be infected with a wAu-like Wolbachia. Moreover, we observed that all Drosophila willistoni samples tested with the VNTR-141 marker harbor the same Wolbachia variant, wWil, either in populations from the South or the North of Brazil. Horizontal transfer events involving species of Old World immigrants and Neotropical species of the willistoni subgroup are discussed.
authors.affiliation: Laboratório de Drosophila, Departamento de Genética, Programa de Pós Graduação em Genética e Biologia Molecular (PPGBM), Instituto de Biociências, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil. Electronic address: muller.genetica@gmail.com.
authors.forename: Mário Josias
authors.initials: MJ
authors.lastname: Müller
authors.forename: Natália Carolina Drebes
authors.initials: NC
authors.lastname: Dörr
authors.forename: Maríndia
authors.initials: M
authors.lastname: Deprá
authors.forename: Hermes José
authors.initials: HJ
authors.lastname: Schmitz
authors.forename: Victor Hugo
authors.initials: VH
authors.lastname: Valiati
authors.forename: Vera Lúcia da Silva
authors.initials: VL
authors.lastname: Valente
mesh_terms: D000818:Animals; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004330:Drosophila / Q000235:genetics* / Q000382:microbiology*; D005260:Female; D017344:Genes, Insect / Q000235:genetics; D008297:Male; D018598:Minisatellite Repeats / Q000235:genetics; D013559:Symbiosis / Q000235:genetics*; D020577:Wolbachia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial
keywords: Dot-blot; VNTR-141; Wolbachia low-titer; qPCR; wsp