title: Wolbachia transfer from Rhagoletis cerasi to Drosophila simulans: investigating the outcomes of host-symbiont coevolution.
abstract: Wolbachia is an endosymbiont of diverse arthropod lineages that can induce various alterations of host reproduction for its own benefice. Cytoplasmic incompatibility (CI) is the most common phenomenon, which results in embryonic lethality when males that bear Wolbachia are mated with females that do not. In the cherry fruit fly, Rhagoletis cerasi, Wolbachia seems to be responsible for previously reported patterns of incompatibility between populations. Here we report on the artificial transfer of two Wolbachia variants (wCer1 and wCer2) from R. cerasi into Drosophila simulans, which was performed with two major goals in mind: first, to isolate wCer1 from wCer2 in order to individually test their respective abilities to induce CI in the new host; and, second, to test the theoretical prediction that recent Wolbachia-host associations should be characterized by high levels of CI, fitness costs to the new host, and inefficient transmission from mothers to offspring. wCer1 was unable to develop in the new host, resulting in its rapid loss after successful injection, while wCer2 was established in the new host. Transmission rates of wCer2 were low, and the infection showed negative fitness effects, consistent with our prediction, but CI levels were unexpectedly lower in the new host. Based on these parameter estimates, neither wCer1 nor wCer2 could be naturally maintained in D. simulans. The experiment thus suggests that natural Wolbachia transfer between species might be restricted by many factors, should the ecological barriers be bypassed.
authors.affiliation: Institute of Forest Entomology, Forest Pathology and Forest Protection, BOKU-University of Natural Resources and Applied Life Sciences, 1190 Vienna, Austria. mriegler@zen.uq.edu.au
authors.forename: Markus
authors.initials: M
authors.lastname: Riegler
authors.forename: Sylvain
authors.initials: S
authors.lastname: Charlat
authors.forename: Christian
authors.initials: C
authors.lastname: Stauffer
authors.forename: Hervé
authors.initials: H
authors.lastname: Merçot
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003433:Crosses, Genetic; D004330:Drosophila / Q000382:microbiology* / Q000502:physiology; D029721:Drosophila Proteins; D005260:Female; D051717:Fushi Tarazu Transcription Factors; D020459:Genes, rRNA; D018398:Homeodomain Proteins / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013559:Symbiosis; D033621:Tephritidae / Q000382:microbiology* / Q000502:physiology; D020577:Wolbachia / Q000235:genetics / Q000502:physiology*
chemical_list: D029721:Drosophila Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D012336:RNA, Ribosomal, 16S; C497169:ftz protein, Drosophila