title: A novel astrovirus species in the gut of yaks with  diarrhoea in the Qinghai–Tibetan Plateau, 2013.
abstract: The yak (Bos grunniens) is an iconic symbol in the high-altitude region of the Qinghai–Tibetan Plateau. Diarrhoea is a common disease in yaks, resulting in major economic losses. To investigate the diversity of viral species, we reported the metagenomics-derived virome in a pooled faecal sample of 20 diarrhoeic yaks. The nine viruses found in the pooled diarrhoeic samples, in order of abundance of nucleic acid sequence, were influenza A virus, bovine viral diarrhoea virus (BVDV), rotavirus, ungulate tetraparvovirus 1 (bovine hokovirus), astrovirus (AstV), bovine enterovirus, hepatitis E virus, kobuvirus and woodchuck hepatitis virus. Compared with healthy yaks, only AstV had a significantly higher prevalence rate in diarrhoeal samples, indicating a correlation with the clinical symptoms of diarrhoea in yaks. To further investigate the molecular characterization of yak AstV, a near-full genome was obtained from a diarrhoeic sample. It was 6243 bp in length and shared 46.4–66.2 % similarity with other related bovine AstVs from faeces. Phylogenetic analysis of the genome demonstrated that the yak AstV fell within the bovine AstVs cluster, but was located in a unique lineage, suggesting a novel AstV species was identified in yaks. Interestingly, the ORF2 region of yak AstV had closer similarity and genetically relationship with deer AstV strain CcAstV-2 than that of the bovine AstVs. Further analysis showed that one possible interspecies recombination event occurred in ORF2. In summary, this study expanded our understanding of the viral communities of diarrhoeal yaks and identified a novel AstV that was associated with diarrhoea in yaks.
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu, PR China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu, PR China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yue
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu, PR China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu, PR China.
authors.forename: Fang
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Animal Virology of the Ministry of Agriculture, State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Lanzhou, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: College of Life Science and Technology, Southwest University for Nationalities, Chengdu, PR China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Tang
mesh_terms: D000818:Animals; D019200:Astroviridae / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D019350:Astroviridae Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000821:virology*; D002681:China / Q000453:epidemiology; D003967:Diarrhea / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D005243:Feces / Q000821:virology; D010802:Phylogeny