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ARS Home » Pacific West Area » Wapato, Washington » Temperate Tree Fruit and Vegetable Research » Research » Publications at this Location » Publication #382864

Research Project: Integrated Approach to Manage the Pest Complex on Temperate Tree Fruits

Location: Temperate Tree Fruit and Vegetable Research

Title: Testing the potential contribution of Wolbachia to speciation when cytoplasmic incompatibility becomes associated with host-related reproductive isolation

item BRUZZESE, DANIEL - University Of Notre Dame
item SCHULER, HANNES - Free University Of Bozen-Bolzano
item WOLFE, THOMAS - University Of Natural Resources And Life Sciences, Vienna
item GOVER, MARY - University Of Notre Dame
item MASTRONI, JOSEPH - University Of Notre Dame
item DOELLMAN, MEREDITH - University Of Notre Dame
item TAIT, CHEYENNE - University Of Notre Dame
item Yee, Wee
item RULL, JUAN - Institute De Ecologia - Mexico
item ALUJA, MARTIN - Institute De Ecologia - Mexico
item HOOD, GLEN - Wayne State University
item GOUGHNOUR, ROBERT - Washington State University
item NOSIL, PATRCIK - National Center For Scientific Research
item FEDER, JEFFERY - University Of Notre Dame

Submitted to: Molecular Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/25/2021
Publication Date: 8/29/2021
Citation: Bruzzese, D.J., Schuler, H., Wolfe, T.M., Gover, M.M., Mastroni, J., Doellman, M.M., Tait, C., Yee, W.L., Rull, J., Aluja, M., Hood, G.R., Goughnour, R., Nosil, P., Feder, J.L. 2021. Wolbachia-induced cytoplasmic incompatibility and its coupling with non-endosymbiont based reproductive isolation during speciation in cherry-infesting Rhagoletis fruit flies. Molecular Ecology.

Interpretive Summary: Inability of insects to produce living offspring after mating caused by bacteria may play an important role in development of new insect species. However, whether this can impede hybridization between species and affect the speciation process remains an open question. Personnel at the University of Notre Dame, IN, Free University of Bozen-Bolzano, Italy, Institute for Forest Entomology, Forest Pathology and Forest Protection, Boku, Vienna, Austria, Instituto de Ecología, A.C., Xalapa, México, Wayne State University, MI, Washington State University, Centre d’Ecologie Fonctionelle et Evolutive, Montpellier, France, and USDA-ARS in Wapato, WA conducted studies on mating compatibility between and bacterial strains of two different cherry fruit fly species across North America to find answers to this question. Results showed that there were varying degrees of mating incompatibility among populations of the two flies and that different strains of bacteria are present among fly populations. Results are important in that providence evidence that both mating incompatibility and bacteria could possibly play roles in isolating insect species and furthering the species divergence process

Technical Abstract: Endosymbiont induced cytoplasmic incompatibility (CI) may play an important role in animal speciation. Yet, whether CI can consistently couple with other nuclear-based forms of reproductive isolation (RI) to sufficiently impede the transfer of endosymbionts between hybridizing populations and further the divergence process remains an open question. Here, we show that varying degrees of pre- and post-mating RI exist among allopatric populations of two cherry-infesting Tephritid fruit flies, Rhagoletis cingulata (Loew) and R. indifferens Curran, across North America. We report evidence for unidirectional CI in cherry flies, implicating a Wolbachia B supergroup strain wCin3 present in Southwestern and Mexican populations as its cause. The current strength of coupling of CI-with other RI barriers approximates, but does not clearly exceed, levels needed to prevent wCin3 from introgressing if infected Southwestern and uninfected Eastern and Pacific Northwest USA populations were to come into secondary contact. Thus, if vertical transmission rates from mother to offspring are high or non-endosymbiont related RI were to weaken only slightly in the contact zone, then wCin3 would spread. In contrast, cytoplasmic-nuclear coupling may be sufficient to impede the transfer of wCin3 if Mexican and USA populations came into secondary contact. We discuss our results in the context of the general paucity of examples demonstrating stable Wolbachia hybrid zones. The challenge remains to determine whether the self-interest of Wolbachia to spread between taxa can be constrained in hybrid zones for long and often enough for the endosymbiont to participate in furthering speciation