Deceptive single-locus taxonomy and phylogeography: Wolbachia-associated divergence in mitochondrial DNA is not reflected in morphology and nuclear markers in a butterfly species.
The satyrine butterfly Coenonympha tullia (Nymphalidae: Satyrinae) displays a deep split between two mitochondrial clades, one restricted to northern Alberta, Canada, and the other found throughout Alberta and across North America. We confirm this deep divide and test hypotheses explaining its phylogeographic structure. Neither genitalia morphology nor nuclear gene sequence supports cryptic species as an explanation, instead indicating differences between nuclear and mitochondrial genome histories. Sex-biased dispersal is unlikely to cause such mito-nuclear differences; however, selective sweeps by reproductive parasites could have led to this conflict. About half of the tested samples were infected by Wolbachia bacteria. Using multilocus strain typing for three Wolbachia genes, we show that the divergent mitochondrial clades are associated with two different Wolbachia strains, supporting the hypothesis that the mito-nuclear differences resulted from selection on the mitochondrial genome due to selective sweeps by Wolbachia strains.
School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, CET College campus Thiruvananthapuram, 695016, India ; Department of Zoology, Stockholm University 106 91, Stockholm, Sweden.
Ullasa
U
Kodandaramaiah
Department of Life Sciences, Natural History Museum Cromwell Road, London, SW7 5BD, U.K ; Department of Biological Sciences, University of Alberta Edmonton, AB T6G 2E9, Canada.
Thomas J
TJ
Simonsen
Department of Biological Sciences, University of Alberta Edmonton, AB T6G 2E9, Canada.
Sean
S
Bromilow
Laboratory of Genetics, Department of Biology, University of Turku 20014, Turku, Finland.
Niklas
N
Wahlberg
Department of Biological Sciences, University of Alberta Edmonton, AB T6G 2E9, Canada.
Felix
F
Sperling
Coenonympha california; Coenonympha nipisiquit; Coenonympha tullia; Wolbachia.; cryptic diversity; incipient species; phylogeography