title: Dicrocoelium chinensis and Dicrocoelium dendriticum (Trematoda: Digenea) are distinct lancet fluke species based on mitochondrial and nuclear ribosomal DNA sequences.
abstract: Lancet flukes parasitize the bile ducts and gall bladder of a range of mammals, including humans, causing dicrocoeliosis. In the present study, we sequenced and characterized the complete mitochondrial (mt) genomes as well as the first and second internal transcribed spacers (ITS-1 and ITS-2=ITS) of nuclear ribosomal DNA (rDNA) of two lancet flukes, Dicrocoelium chinensis and D. dendriticum. Sequence comparison of a conserved mt gene and nuclear rDNA sequences among multiple individual lancet flukes revealed substantial nucleotide differences between the species but limited sequence variation within each of them. Phylogenetic analysis of the concatenated amino acid and multiple mt rrnS sequences using Bayesian inference supported the separation of D. chinensis and D. dendriticum into two distinct species-specific clades. Results of the present study support the proposal that D. dendriticum and D. chinensis represent two distinct lancet flukes. While providing the first mt genomes from members of the superfamily Plagiorchioidea, the novel mt markers described herein will be useful for further studies of the diagnosis, epidemiology and systematics of the lancet flukes and other trematodes of human and animal health significance.
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
authors.forename: Guo-Hua
authors.initials: GH
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China.
authors.forename: Hong-Bin
authors.initials: HB
authors.lastname: Yan
authors.affiliation: Dipartimento di Sanità Pubblica e Zootecnia, Università degli Studi di Bari, 70010 Valenzano, Bari, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Otranto
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China; College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China.
authors.forename: Xing-Ye
authors.initials: XY
authors.lastname: Wang
authors.affiliation: College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China.
authors.forename: Guang-Hui
authors.initials: GH
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China. Electronic address: jiawanzhong@caas.cn.
authors.forename: Wan-Zhong
authors.initials: WZ
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China. Electronic address: xingquanzhu1@hotmail.com.
authors.forename: Xing-Quan
authors.initials: XQ
authors.lastname: Zhu
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D018509:DNA, Helminth / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D004013:Dicrocoelium / Q000145:classification* / Q000235:genetics; D014644:Genetic Variation; D054629:Genome, Mitochondrial; D058977:Molecular Sequence Annotation; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D018509:DNA, Helminth; D021903:DNA, Ribosomal Spacer
keywords: Dicrocoelium chinensis; Dicrocoelium dendriticum; Evolution; Mitochondrial DNA; Nuclear ribosomal DNA; Phylogeny