Acta Veterinaria et Zootechnica Sinica ›› 2021, Vol. 52 ›› Issue (2): 469-477.doi: 10.11843/j.issn.0366-6964.2021.02.019

• PREVENTIVE VETERINARY MEDICINE • Previous Articles     Next Articles

Detection and Genomic Characteristics of Bovine Torovirus in Yak

ZHAO Long1, TANG Cheng1,2, YUE Hua1,2*   

  1. 1. College of Animal&Veterinary Science, Southwest Minzu University, Chengdu 610041, China;
    2. Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization, Chengdu 610041, China
  • Received:2020-06-09 Online:2021-02-23 Published:2021-02-24

Abstract: The purpose of this study was to investigate the presence of bovine torovirus (BToV) in yak in Qinghai-Tibetan Plateau and to analyze the characteristics of the BToV genome. An RT-PCR assay was used to detect BToV from clinical samples from Tibet, Qinghai and Sichuan, and the BToV genome was further amplified from the positive sample. Approximate 6.9% (10/145) diarrheic samples were detected as BToV positive, and the positive rate in Tibet, Qinghai and Sichuan was 11.8%, 8.9% and 3.0% respectively. Moreover, a complete BToV genomic sequence was obtained from a positive sample, which was 28 314 nucleotides in length with a GC content of 36.31%. The genome in this study shared 82%-97% nucleotide sequence identity with the 5 BToV genomic sequences in the GenBank database. It shared the highest sequence identity and the closest genetic relationship with the native BToV genome SC2. Compared with all 14 complete BToV-S gene sequences in the GenBank database, the S gene of the BToV genome in this study had 8 unique amino acid variations which include 6 variations in the S1 domain and 2 variations in the S2 domain. Besides, a recombinant event was predicted in the region of 222-2 473 bp of the S gene. In conclusion, this research revealed that BToV could infect yak with wide geographical distribution. Furthermore, a genotype Ⅲ BToV genome was obtained, and a recombinant event was predicted in its S gene. The results of this study would be helpful for a better understanding of BToV's molecular characteristics and genetic evolution.

Key words: yak, bovine torovirus, genome, S gene recombination

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