title: Mitochondrial DNA variants help monitor the dynamics of Wolbachia invasion into host populations.
abstract: Wolbachia is the most widespread endosymbiotic bacterium of insects and other arthropods that can rapidly invade host populations. Deliberate releases of Wolbachia into natural populations of the dengue fever mosquito, Aedes aegypti, are used as a novel biocontrol strategy for dengue suppression. Invasion of Wolbachia through the host population relies on factors such as high fidelity of the endosymbiont transmission and limited immigration of uninfected individuals, but these factors can be difficult to measure. One way of acquiring relevant information is to consider mitochondrial DNA (mtDNA) variation alongside Wolbachia in field-caught mosquitoes. Here we used diagnostic mtDNA markers to differentiate infection-associated mtDNA haplotypes from those of the uninfected mosquitoes at release sites. Unique haplotypes associated with Wolbachia were found at locations outside Australia. We also performed mathematical and qualitative analyses including modelling the expected dynamics of the Wolbachia and mtDNA variants during and after a release. Our analyses identified key features in haplotype frequency patterns to infer the presence of imperfect maternal transmission of Wolbachia, presence of immigration and possibly incomplete cytoplasmic incompatibility. We demonstrate that ongoing screening of the mtDNA variants should provide information on maternal leakage and immigration, particularly in releases outside Australia. As we demonstrate in a case study, our models to track the Wolbachia dynamics can be successfully applied to temporal studies in natural populations or Wolbachia release programs, as long as there is co-occurring mtDNA variation that differentiates infected and uninfected populations.
authors.affiliation: Pest and Environmental Adaptation Research Group (PEARG), School of BioSciences, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: H L
authors.initials: HL
authors.lastname: Yeap
authors.affiliation: Pest and Environmental Adaptation Research Group (PEARG), School of BioSciences, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: G
authors.initials: G
authors.lastname: Rašić
authors.affiliation: Pest and Environmental Adaptation Research Group (PEARG), School of BioSciences, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: N M
authors.initials: NM
authors.lastname: Endersby-Harshman
authors.affiliation: Pest and Environmental Adaptation Research Group (PEARG), School of BioSciences, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: S F
authors.initials: SF
authors.lastname: Lee
authors.affiliation: Faculty of Medicine, Universitas Gadjah Mada, Jl. Farmako, Sekip Utara, Yogyakarta, Indonesia.
authors.forename: E
authors.initials: E
authors.lastname: Arguni
authors.affiliation: Laboratory of Medical Entomology, National Institute of Hygiene and Epidemiology, Hanoi, Vietnam.
authors.forename: H
authors.initials: H
authors.lastname: Le Nguyen
authors.affiliation: Pest and Environmental Adaptation Research Group (PEARG), School of BioSciences, Bio21 Institute, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: A A
authors.initials: AA
authors.lastname: Hoffmann
mesh_terms: D000330:Aedes / Q000235:genetics* / Q000382:microbiology*; D000818:Animals; D001315:Australia; D004272:DNA, Mitochondrial / Q000235:genetics*; D005819:Genetic Markers; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes; D007303:Insect Vectors / Q000235:genetics / Q000382:microbiology; D008954:Models, Biological; D008957:Models, Genetic; D010572:Pest Control, Biological; D020577:Wolbachia
chemical_list: D004272:DNA, Mitochondrial; D005819:Genetic Markers