title: Molecular approaches to differentiate three species of Nematodirus in sheep and goats from China based on internal transcribed spacer rDNA sequences.
abstract: Internal transcribed spacer (ITS) rDNA sequences of three Nematodirus species from naturally infected goats or sheep in two endemic provinces of China were analysed to establish an effective molecular approach to differentiate Nematodirus species in small ruminants. The respective intra-specific genetic variations in ITS1 and ITS2 rDNA regions were 0.3-1.8% and 0-0.4% in N. spathiger, 0-6.5% and 0-5.4% in N. helvetianus, and 0-4.4% and 0-6.1% in N. oiratianus from China. The respective intra-specific variations of ITS1 and ITS2 were 1.8-4.4% and 1.6-6.1% between N. oiratianus isolates from China and Iran, 5.7-7.1% and 6.3-8.3% between N. helvetianus samples from China and America. For N. spathiger, compared with samples from China, sequence differences in ITS1 rDNA were 0.3-2.4% in isolates from America, 0.3-2.9% in New Zealand and 2.1-2.4% in Australia. Genetic variations in ITS2 rDNA of N. spathiger were 0-0.4% between samples from China and America, and 0-0.8% between samples from China and New Zealand. Using mutation sites, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and specific PCR techniques were developed to differentiate these three Nematodirus species. The specific PCR assay allowed the accurate identification of N. oiratianus from other common nematodes with a sensitivity of 0.69 pg and further examination of Nematodirus samples demonstrated the reliability of these two molecular methods.
authors: College of Veterinary Medicine, Northwest A&F University,Yangling712100,Shaanxi Province,PR China.
authors: G H
authors: GH
authors: Zhao
authors: College of Veterinary Medicine, Northwest A&F University,Yangling712100,Shaanxi Province,PR China.
authors: Y Q
authors: YQ
authors: Jia
authors: College of Veterinary Medicine, Northwest A&F University,Yangling712100,Shaanxi Province,PR China.
authors: Q Q
authors: QQ
authors: Bian
authors: Parasitology Division, Moredun Research Institute,Pentlands Science Park,MidlothianEH26 0PZ,Scotland,UK.
authors: A J
authors: AJ
authors: Nisbet
authors: College of Veterinary Medicine, Northwest A&F University,Yangling712100,Shaanxi Province,PR China.
authors: W Y
authors: WY
authors: Cheng
authors: College of Veterinary Medicine, Northwest A&F University,Yangling712100,Shaanxi Province,PR China.
authors: Y
authors: Y
authors: Liu
authors: College of Veterinary Medicine, Northwest A&F University,Yangling712100,Shaanxi Province,PR China.
authors: Y Q
authors: YQ
authors: Fang
authors: College of Veterinary Medicine, Northwest A&F University,Yangling712100,Shaanxi Province,PR China.
authors: X T
authors: XT
authors: Ma
authors: College of Veterinary Medicine, Northwest A&F University,Yangling712100,Shaanxi Province,PR China.
authors: S K
authors: SK
authors: Yu
mesh_terms: D000818:Animals; D002681:China; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation; D015511:Goat Diseases / Q000469:parasitology*; D006041:Goats; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D008969:Molecular Sequence Data; D057808:Nematodirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D012756:Sheep; D012757:Sheep Diseases / Q000469:parasitology*; D017206:Strongylida Infections / Q000469:parasitology / Q000662:veterinary*
chemical_list: D017931:DNA Primers; D018509:DNA, Helminth; D021903:DNA, Ribosomal Spacer