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United States Department of Agriculture

Agricultural Research Service

Research Project: INTEGRATED BIOSYSTEMATICS AND TAXONOMY FOR PARASITES AMONG UNGULATES AND OTHER VERTEBRATES Title: Phylogeography of a Holarctic Nematode: Soboliphyme Baturini among Mustelids: Climate Change, Episodic Colonization and Diversification in a Complex Host-Parasite System

Authors
item Koehler, A V - U NEW MEXICO ALBUQUERQUE
item Hoberg, Eric
item Dokuchaev, N - MADAGAN. RUSSIA
item Tranbenkova, N - RUSSIA
item Whitman, J - FAIRBANKS, ALASKA
item Nagorsen, D - VICTORIA, CANADA
item Cook, J - U NEW MEXICO ALBUQUERQUE

Submitted to: Biological Journal of the Linnean Society, London
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 2008
Publication Date: March 1, 2009
Citation: Koehler, A.A., Hoberg, E.P., Dokuchaev, N.E., Tranbenkova, N.A., Whitman, J.S., Nagorsen, D.W., Cook, J.A. 2009. Phylogiography of a Holarctic nematode: Soboliphyme baturini among Mustelids: Climate change, episodic colonization and diversification in a complex host-parasite system. Biological Journal of the Linnean Society, London. 97(3):467-708.

Interpretive Summary: The history of distribution and the structure of populations among parasitic nematodes are poorly understood and most studies have explored parasites in ruminants, carnivores and humans. Interpretations of distribution also emerges from studies that link information about the physical processes in earth history, and the evolution of host groups. In a model system we explored the population structure and biogeography (phylogeography) for the large gastric nematode, Soboliphyme baturini, in mustelid hosts in North America and adjacent regions of Eurasia. Within S. baturini, a host-specific partition in North America between martens (Martes caurina and M. americana) was not identified. Instead, the substantial geographic structure within S. baturini relates to the dynamic geologic history of this northern region and especially the North Pacific Coast. Beringia (th region that has formed a connection linking North America and Eurasia) and other coastal refugia along the western margin of North America played a large role during glacial maxima in the maintenance and divergence of the parasite. Biotic expansion (dispersal) and geographic colonization across the Bering Land Bridge and the Holarctic during glacial maxima in the Pleistocene (over the past 2 million years) appear to have driven host-switching among mustelids, especially in populations now distributed in eastern Beringia. These results contribute to a growing body of evidence about how parasite faunas develop in space and time. Of fundamental interest is the idea that geographic factors rather than associations with particular hosts serve as important limits on evolution and the distribution of parasite species. Further indicated is the critical importance of the Beringian region as a determinant of faunal structure in North America establishing this as a significant zone in the overall history for parasites not only in carnivores but those in ruminants and a number of groups that are zoonoses (transmissible from animal hosts) in humans.

Technical Abstract: : Phylogeography of Soboliphyme baturini, a nematode parasite in mustelids, is explored across Beringia. Sequences of the mitochondrial cytochrome c oxidase subunit 1 (COI) and nicotinamide adenine dinucleotide dehydrogenase subunit 4 (ND4) genes were evaluated from 38 individuals representing 19 localities throughout Alaska, Canada and Siberia. A total of 30 haplotypes was recovered and maximum parsimony and Bayesian phylogenetic analyses support recognition of a single species with a distribution extending from the Palearctic to the Nearctic. Within S. baturini, a host-specific partition in North America between Martes caurina and M. americana was not identified. Instead, the substantial geographic structure within S. baturini relates to the dynamic geologic history of this northern region and especially the North Pacific Coast. Beringia and other coastal refugia along the western margin of North America played a large role during stadial maxima in the maintenance and divergence of the parasite. Biotic expansion and geographic colonization across the Bering Land Bridge and the Holarctic during glacial maxima in the Pleistocene appear to have driven host-switching among mustelids, especially in populations now distributed in eastern Beringia.

Last Modified: 9/2/2014
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