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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: A Molecular Phylogeny for the Protostrongylidae (Nematoda: Metastrongylina)

Authors
item Asmundsson, Ingrid - VISITING SCIENTIST, APDL
item Hoberg, Eric
item Carreno, Ramon - DEPT ZOOL,OH WESLEYAN U
item Kuchboev, Abdurakhim - UZBEK ACAD SCI, UZBEKISTA

Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 22, 2008
Publication Date: N/A

Interpretive Summary: Lungworms and muscleworms (also called Protostrongylidae), are a putative monophyletic group among the nematodes. These parasites are economically important pathogens infecting domestic and free-ranging ungulate and leporid hosts throughout the world. Faunal diversity is centered in Eurasia and North America among ruminants, principally in wild and domestic caprines (sheep and goats) and among cervids (deer, elk, caribou, etc.) although translocation and introductions with various hosts have influenced the global and regional distributions for many species. Following from a comprehensive assessment of evolutionary relationships based on morphology, we reconstructed a molecular phylogeny based on ribosomal DNA (28S) for 15 species in 9 protostrongylid genera, including a previously unrecognized and putative new genus and species recently found in North American ungulates. Analysis of 28S rDNA revealed relationships similar to those previously reported based on morphology, providing strong support for earlier analyses. Host associations for the Protostrongylidae are explored, and the tree topology is found to be consistent with a history of host colonization with pecoran ruminants as ancestral. In conjunction with recent theoretical studies, these results are important in demonstrating the basic processes for diversification of hosts and parasites. Additionally, contemporary events for geographic and host colonization may now represent ongoing processes in dynamic and developing zones of contact for sympatric cervid and caprine host populations in northwestern North America where ranges for parasite assemblages among ungulates are being altered as a consequence of climate warming and habitat perturbation. Emergence of disease in ungulate hosts, attributable to infections of larval and adult protostrongylids, has been recognized in high-latitude ecosystems and is predicted to have an adverse influence on the sustainability of host populations that represent important food resources for subsistence cultures in some regions under a regime of climate change These observations highlight the need to elucidate parasite diversity, historical relationships, and host associations within a phylogenetic context and to develop faunal baselines that contribute to understanding the processes that influence the distribution of complex host-parasite systems.

Technical Abstract: Protostrongylids, a putative monophyletic group among the lungworms (Metastrongylina: Metastrongyloidea), are economically important pathogens infecting domestic and free-ranging ungulate and leporid hosts throughout the world. Here, we reconstruct a molecular phylogeny based on ribosomal DNA (28S) for 15 species in 9 protostrongylid genera, including a previously unrecognized and putative new genus and species recently found in North American ungulates. Analysis of 28S rDNA revealed relationships similar to those previously reported based on morphology. Trees were rooted with Metastrongylus salmi and those inferred by Baeysian analysis, maximum parsimony and maximum likelihood were all similar with high bootstrap support for most of the major relationships. Host associations for the Protostrongylidae are explored, and the tree topology is found to be consistent with a history of host colonization with pecoran ruminants as ancestral. These observations highlight the need to elucidate parasite diversity, historical relationships, and host associations within a phylogenetic context and to develop faunal baselines that contribute to understanding the processes that influence the distribution of complex host-parasite systems.

Last Modified: 4/18/2014
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