Premium
Evidence for gene flow in parasitic nematodes between two host species of shrews
Author(s) -
Brant Sara V.,
Ortí Guillermo
Publication year - 2003
Publication title -
molecular ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.619
H-Index - 225
eISSN - 1365-294X
pISSN - 0962-1083
DOI - 10.1046/j.1365-294x.2003.01927.x
Subject(s) - biology , shrew , mitochondrial dna , gene flow , phylogenetic tree , host (biology) , zoology , nematode , parasite hosting , insectivora , monophyly , phylogenetics , evolutionary biology , ecology , gene , genetic variation , genetics , clade , world wide web , computer science
Abstract We describe the genetic structure of populations of the intestinal nematode Longistriata caudabullata (Trichostrongyloidea: Heligmosomidae), a common parasite of short‐tailed shrews (genus Blarina , Insectivora: Soricidae). Parasites and hosts were collected from a transect across a contact zone between two species of hosts, Blarina brevicauda and B. hylophaga, in central North America. An 800‐base pairs (bp) fragment of the ND4 mitochondrial DNA (mtDNA) gene was sequenced for 28 worms and a 783‐bp fragment of the mtDNA control region was analysed for 16 shrews. Phylogenetic analyses of mtDNA sequences revealed reciprocal monophyly for the shrew species, concordant with morphological diagnosis, and supported the idea that the transect cuts through a secondary contact zone between well‐differentiated B. brevicauda and B. hylophaga . In contrast to this pattern, the parasitic nematode mtDNA phylogeny was not subdivided according to host affiliation. Genealogical discordance between parasite and host phylogenies suggests extensive gene flow among parasites across the host species boundary.