title: Mitochondrial DNA sequences of 37 collar-spined echinostomes (Digenea: Echinostomatidae) in Thailand and Lao PDR reveals presence of two species: Echinostoma revolutum and E. miyagawai.
abstract: The "37 collar-spined" or "revolutum" group of echinostomes is recognized as a species complex. The identification of members of this complex by morphological taxonomic characters is difficult and confusing, and hence, molecular analyses are a useful alternative method for molecular systematic studies. The current study examined the genetic diversity of those 37 collar-spined echinostomes which are recognized morphologically as Echinostoma revolutum in Thailand and Lao PDR using the cytochrome c oxidase subunit 1 (CO1) and the NADH dehydrogenase subunit 1 (ND1) sequences. On the basis of molecular investigations, at least two species of 37 collar-spined echinostomes exist in Southeast Asia, namely E. revolutum and Echinostoma miyagawai. The specimens examined in this study, coming from ducks in Thailand and Lao PDR, were compared to isolates from America, Europe and Australia for which DNA sequences are available in public databases. Haplotype analysis detected 6 and 26 haplotypes when comparing the CO1 sequences of E. revolutum and E. miyagawai, respectively, from different geographical isolates from Thailand and Lao PDR. The phylogenetic trees, ND1 haplotype network and genetic differentiation (ɸST) analyses showed that E. revolutum were genetically different on a continental scale, i.e. Eurasian and American lineages.
authors.affiliation: Division of Environmental Health Sciences, Kochi Medical School, Kochi University, Oko, Nankoku 783-8505, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Nagataki
authors.affiliation: Division of Cell Biology, Department of Preclinical Sciences, Faculty of Medicine, Thammasat University, Rangsit Campus, Pathum Thani 12120, Thailand.
authors.forename: Chairat
authors.initials: C
authors.lastname: Tantrawatpan
authors.affiliation: Division of Environmental Health Sciences, Kochi Medical School, Kochi University, Oko, Nankoku 783-8505, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Agatsuma
authors.affiliation: Department of Clinical Laboratory Medicine, Kochi Medical School, Kochi University, Oko, Nankoku 783-8505, Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Sugiura
authors.affiliation: Department of Public Health, Faculty of Science and Technology, Phetchabun Rajabhat University, Phetchabun 67000, Thailand.
authors.forename: Kunyarat
authors.initials: K
authors.lastname: Duenngai
authors.affiliation: Liver Fluke and Cholangiocarcinoma Research Center (LFCRC), Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Paiboon
authors.initials: P
authors.lastname: Sithithaworn
authors.affiliation: Liver Fluke and Cholangiocarcinoma Research Center (LFCRC), Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Imperial College London, Faculty of Medicine, St Mary's Campus, South Wharf Street, London W2 1NY, United Kingdom; Cholangiocarcinoma Screening and Care Program, Faculty of Medicine, Khon Kaen Univeristy, Khon Kaen 40002, Thailand.
authors.forename: Ross H
authors.initials: RH
authors.lastname: Andrews
authors.affiliation: Institute of Zoology 1: Ecology and Parasitology, University of Karlsruhe, Kornblumen Strasse 13, Karlsruhe, Germany; Cholangiocarcinoma Screening and Care Program, Faculty of Medicine, Khon Kaen Univeristy, Khon Kaen 40002, Thailand.
authors.forename: Trevor N
authors.initials: TN
authors.lastname: Petney
authors.affiliation: Walai Rukhavej Botanical Research Institute (WRBRI), Mahasarakham University, Maha Sarakham 44150, Thailand. Electronic address: weerachai.s@msu.ac.th.
authors.forename: Weerachai
authors.initials: W
authors.lastname: Saijuntha
mesh_terms: D000818:Animals; D018509:DNA, Helminth / Q000032:analysis; D004272:DNA, Mitochondrial / Q000032:analysis*; D004372:Ducks / Q000469:parasitology*; D004449:Echinostoma / Q000145:classification* / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000032:analysis; D014644:Genetic Variation; D006239:Haplotypes; D007812:Laos; D008928:Mitochondria / Q000235:genetics*; D009245:NADH Dehydrogenase / Q000032:analysis; D010802:Phylogeny; D058974:Phylogeography; D017422:Sequence Analysis, DNA / Q000379:methods*; D013785:Thailand
chemical_list: D018509:DNA, Helminth; D004272:DNA, Mitochondrial; D009245:NADH Dehydrogenase; D003576:Electron Transport Complex IV
keywords: 37 collar-spined; Echinostoma miyagawai; Echinostoma revolutum; Echinostome; Mitochondrial gene; The “revolutum” group