title: Selective sweep of Wolbachia and parthenogenetic host genomes - the example of the weevil Eusomus ovulum.
abstract: Most parthenogenetic weevil species are postulated to have originated via hybridization, but Wolbachia has also been speculated to play a role via the induction of parthenogenesis. Here, we examine the molecular diversity of Wolbachia and parthenogenetic host genomes. The host species studied here, Eusomus ovulum, is known to be exclusively parthenogenetic and triploid. The E. ovulum populations that we examined had a low genetic diversity of mitochondrial (cytochrome oxidase I gene) and nuclear markers (internal transcribed spacer 2 and elongation factor 1-α gene), and they all were infected by only single bacteria strains (genotyped for five genes according to the multilocus sequence typing system). We found significant signs of linkage disequilibrium and a lack of recombination amongst all of the examined genomes (bacteria and host), which strongly indicates a selective sweep. The lack of heterozygosity in host nuclear genes, missing bisexual populations and selective sweep between the parthenogenetic host and bacteria genomes suggest that parthenogenesis in this species could have originated as a result of infection rather than hybridization. However, the finding that highly similar Wolbachia strains are also present in other parthenogenetic weevils from the same habitat suggests the opposite scenario: bacteria may have infected the already parthenogenetic lineage and taken advantage of the host's unisexual reproduction.
authors.affiliation: Center for Biodiversity Studies, Department of Biosystematics, Opole University, Opole, Poland.
authors.forename: M A
authors.initials: MA
authors.lastname: Mazur
authors.affiliation: Department of Zoology, Comenius University, Bratislava, Slovakia.
authors.forename: M
authors.initials: M
authors.lastname: Holecová
authors.affiliation: Institute of Zoology, Jagiellonian University, Krakow, Poland.
authors.forename: D
authors.initials: D
authors.lastname: Lachowska-Cierlik
authors.affiliation: Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Krakow, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Lis
authors.affiliation: Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Krakow, Poland.
authors.forename: D
authors.initials: D
authors.lastname: Kubisz
authors.affiliation: Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Krakow, Poland.
authors.forename: Ł
authors.identifier: 0000-0001-7345-9400
authors.initials: Ł
authors.lastname: Kajtoch
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D021903:DNA, Ribosomal Spacer / Q000235:genetics / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism; D005260:Female; D005798:Genes, Bacterial; D014644:Genetic Variation; D049750:Genome, Insect; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D015810:Linkage Disequilibrium; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D058885:Multilocus Sequence Typing; D010312:Parthenogenesis; D020648:Peptide Elongation Factor 1 / Q000235:genetics / Q000378:metabolism; D058974:Phylogeography; D017422:Sequence Analysis, DNA; D048889:Weevils / Q000235:genetics* / Q000382:microbiology; D020577:Wolbachia / Q000235:genetics / Q000502:physiology*
chemical_list: D021903:DNA, Ribosomal Spacer; D019476:Insect Proteins; D024101:Mitochondrial Proteins; D020648:Peptide Elongation Factor 1; D003576:Electron Transport Complex IV
keywords: Coleoptera; Curculionidae; Eusomus ovulum; Rickettsiales; Wolbachia; endosymbiosis; parthenogenesis; selective sweep