title: Mitochondrial and nuclear ribosomal DNA dataset supports that Paramphistomum leydeni (Trematoda: Digenea) is a distinct rumen fluke species.
abstract: BACKGROUND
  Rumen flukes parasitize the rumen and reticulum of ruminants, causing paramphistomiasis. Over the years, there has been considerable debate as to whether Paramphistomum leydeni and Paramphistomum cervi are the same or distant species.
  
  
  METHODS
  In the present study, the complete mitochondrial (mt) genome of P. leydeni was amplified using PCR-based sequencing and compared with that of P. cervi. The second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA (rDNA) of P. leydeni specimens (n = 6) and P. cervi specimens (n = 8) was amplified and then sequenced. Phylogenetic relationship of the concatenated amino acid sequence data for 12 protein-coding genes of the two rumen flukes and selected members of Trematoda was evaluated using Bayesian inference (BI).
  
  
  RESULTS
  The complete mt genome of P. leydeni was 14,050 bp in size. Significant nucleotide difference between the P. leydeni mt genome and that of P. cervi (14.7%) was observed. For genetic divergence in ITS-2, sequence difference between P. leydeni and P. cervi was 3.1%, while no sequence variation was detected within each of them. Phylogenetic analysis indicated that P. leydeni and P. cervi are closely-related but distinct rumen flukes.
  
  
  CONCLUSIONS
  Results of the present study support the proposal that P. leydeni and P. cervi represent two distinct valid species. The mt genome sequences of P. leydeni provide plentiful resources of mitochondrial markers, which can be combined with nuclear markers, for further comparative studies of the biology of P. leydeni and its congeners from China and other countries.
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. dreamerjm@163.com.|College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan Province, 410128, PR China. dreamerjm@163.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
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. hejunjun617@163.com.
authors.forename: Jun-Jun
authors.initials: JJ
authors.lastname: He
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. liuguohua5202008@163.com.
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. zhoudonghui@caas.cn.
authors.forename: Dong-Hui
authors.initials: DH
authors.lastname: Zhou
authors.affiliation: Institute of Livestock Research, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, Tibet Autonomous Region, 850009, PR China. tibetliujianzhi@163.com.
authors.forename: Jian-Zhi
authors.initials: JZ
authors.lastname: Liu
authors.affiliation: College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan Province, 410128, PR China. yiliupro@163.com.
authors.forename: Yi
authors.initials: Y
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. xingquanzhu1@hotmail.com.|College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan Province, 410128, PR China. xingquanzhu1@hotmail.com.|Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, Jiangsu Province, 225009, PR China. xingquanzhu1@hotmail.com.
authors.forename: Xing-Quan
authors.initials: XQ
authors.lastname: Zhu
mesh_terms: D000818:Animals; D002681:China; D016000:Cluster Analysis; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics*; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010250:Paramphistomatidae / Q000145:classification* / Q000235:genetics*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial; D021903:DNA, Ribosomal Spacer