title: Substantial genetic divergence between morphologically indistinguishable populations of Fasciola suggests the possibility of cryptic speciation.
abstract: The liver flukes, Fasciola hepatica and Fasciola gigantica, are considered to be sister species and between them present a major threat worldwide to livestock production. In this study sequence data have been employed from informative regions of the nuclear and mitochondrial genomes of over 200 morphologically F. hepatica-like or F. gigantica-like flukes from Europe, sub-Saharan Africa and South Asia to assess genetic diversity. Evidence is presented for the existence of four well-separated clades: African gigantica-like flukes, Indian gigantica-like flukes, European hepatica-like flukes and African high-altitude hepatica-like flukes. Application of the Biological Species Concept to trematodes is problematic; however, the degree of separation between these groups was sufficient for them to be considered as distinct species using the four times rule for speciation.
authors.affiliation: School of Biological Sciences, The Queen's University of Belfast, Belfast, Northern Ireland, UK.
authors.forename: S M
authors.initials: SM
authors.lastname: Walker
authors.forename: P A
authors.initials: PA
authors.lastname: Prodöhl
authors.forename: E M
authors.initials: EM
authors.lastname: Hoey
authors.forename: I
authors.initials: I
authors.lastname: Fairweather
authors.forename: R E B
authors.initials: RE
authors.lastname: Hanna
authors.forename: G
authors.initials: G
authors.lastname: Brennan
authors.forename: A
authors.initials: A
authors.lastname: Trudgett
mesh_terms: D017954:Africa South of the Sahara / Q000453:epidemiology; D000818:Animals; D001315:Australia / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000469:parasitology; D004272:DNA, Mitochondrial / Q000235:genetics; D018397:Equidae; D005060:Europe / Q000453:epidemiology; D005209:Fasciola / Q000235:genetics*; D005211:Fascioliasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D049810:Genetic Speciation; D014644:Genetic Variation; D016678:Genome; D007194:India / Q000453:epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D018510:RNA, Helminth / Q000235:genetics; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D012756:Sheep; D012757:Sheep Diseases / Q000453:epidemiology / Q000469:parasitology
chemical_list: D004272:DNA, Mitochondrial; D018510:RNA, Helminth; D012339:RNA, Ribosomal, 28S