title: Heligmosomoides neopolygyrus Asakawa & Ohbayashi, 1986, a cryptic Asian nematode infecting the striped field mouse Apodemus agrarius in Central Europe.
abstract: BACKGROUND
  Heligmosomoides polygyrus is a widespread gastro-intestinal nematode infecting wild Apodemus (wood mice) throughout Europe. Using molecular and morphological evidence, we review the status of Heligmosomoides from Apodemus agrarius in Poland previously considered to be an outlying clade of H. polygyrus, to further resolve the status of the laboratory model species, H. bakeri.
  
  
  METHODS
  Morphological analysis of the male bursa and the synlophe, and molecular analyses of concatenated nuclear (28S rDNA, ITS1 and ITS2) and mitochondrial (CO1 and cytb) genes, of Heligmosomoides collected from Apodemus agrarius from two sites in Poland and comparison with related heligmosomids from voles and mice in Eurasia.
  
  
  RESULTS
  Heligmosomoides neopolygyrus, a heligmosomid nematode from Apodemus species from China and Japan, is recognised for the first time in western Europe infecting Apodemus agrarius in Poland. It can be distinguished from H. polygyrus by the filiform externo-dorsal rays of the male copulatory bursa and the small, equally distributed longitudinal crêtes on the body. Specimens from A. agrarius are 20% different at ribosomal (ITS1 and ITS2) nuclear loci, and 10% different at the mitochondrial cytb locus from H. polygyrus, and in phylogenetic analyses group with the vole-infecting genus Heligmosomum.
  
  
  CONCLUSIONS
  Despite morphological similarity, H. neopolygyrus is only distantly related to H. polygyrus from western European Apodemus, and may be more closely related to vole-infecting taxa. It was brought into Europe by the recent rapid migration of the host mice. Inclusion of H. neopolygyrus in phylogenies makes it clear that Heligmosomoides is paraphyletic, with the pika-infecting Ohbayashinema and the vole-infecting Heligmosomum nesting within it. Clarification of the European status of H. neopolygyrus also allows H. bakeri, the laboratory model species, to be seen as a terminal sister clade to H. polygyrus, rather than as an internal clade of the latter taxon.
authors.affiliation: Department of Invertebrate Systematics and Ecology, Institute of Biology, Wrocław University of Environmental and Life Sciences, ul. Kożuchowska 5b, 51-631, Wrocław, Poland. grzegorz.zalesny@up.wroc.pl.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Zaleśny
authors.affiliation: Department of Parasitology, Institute of Genetics and Microbiology, University of Wrocław, ul. Przybyszewskiego 63, 51-148, Wrocław, Poland. joanna.hildebrand@microb.uni.wroc.pl.
authors.forename: Joanna
authors.initials: J
authors.lastname: Hildebrand
authors.affiliation: KIT Biomedical Research, Royal Tropical Institute, Meibergdreef 39, 1105 AZ, Amsterdam, the Netherlands. a.paziewska@kit.nl.
authors.forename: Anna
authors.initials: A
authors.lastname: Paziewska-Harris
authors.affiliation: School of Life Sciences, University of Nottingham, NG2 7RD, Nottingham, UK. jerzy.behnke@nottingham.ac.uk.
authors.forename: Jerzy M
authors.initials: JM
authors.lastname: Behnke
authors.affiliation: Natural History Museum, University of Oslo, P.O. Box 1172, N-0562, Oslo, Norway. p.d.harris@nhm.uio.no.
authors.forename: Philip D
authors.initials: PD
authors.lastname: Harris
mesh_terms: D000818:Animals; D008297:Male; D051189:Murinae; D009349:Nematode Infections / Q000453:epidemiology / Q000662:veterinary*; D017184:Nematospiroides / Q000302:isolation & purification*; D011044:Poland / Q000453:epidemiology; D012376:Rodent Diseases / Q000453:epidemiology / Q000469:parasitology*