China Animal Husbandry and Veterinary Medicine ›› 2020, Vol. 47 ›› Issue (1): 221-228.doi: 10.16431/j.cnki.1671-7236.2020.01.026

• Preventive Veterinary Medicine • Previous Articles     Next Articles

Identification and Complete Genomic Analysis of a Newcastle Disease Virus from a Laying Hen

LI Jiajia1,2, SONG Jianling2   

  1. 1. Southwest Forestry University, Kunming 650224, China;
    2. Yunnan Animal Science and Veterinary Institute, Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory, Kunming 650224, China
  • Received:2019-08-23 Online:2020-01-20 Published:2020-01-17

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Abstract: In order to study the molecular epidemic characteristics and pathogenicity of Newcastle disease virus (NDV) in Yunnan province,the pathogen was isolated from the tissue samples of an laying hens farm in Yunnan province.The isolates were proved to be NDV by hemagglutination,hemagglutination inhibition test and RT-PCR detection.The virulence of the virus was determined by the minimal lethal dose of (MLD),50% egg infectious does of (EID50),the mean death time of (MDT),the pathigenicity index of (ICPI),and the pathogenicity index (IVPI) of intravenous inoculation.The results showed that the EID50 was 10-4.4,MLD was 10-4,MDT was 97.5 h,ICPI was 0 and ICPI was 0,which showed that the isolates were attenuated strains.High throughput sequencing and genetic evolution analysis showed that the genomic length of the isolated strain was 15 198 bp,and there were 6 structural genes from 3'end to 5'end,which were 1-48 nucleotides interval between NP-P-M-F-HN-L genes.The genetic evolution analysis of the whole genome,F gene and HN gene showed that the isolated strain belonged to Class Ⅰ branch.The full length ORF of F gene was 1 662 bp,encoding 553 amino acids,and the amino acid sequence of F protein cracking site was 112-ERQERL-117,which consistent with the characteristics of NDV weak virus cleavage site.The ORF of HN gene was 1 851 bp,encoding 616 amino acids.There was no amino acid sequence variation at 234-NRKSCS-239 site in the conservative region of HN gene.There were six glycosylation sites in F protein and six potential glycosylation sites in HN protein,but there were missing and more glycosylation sites compared with LaSota.The cysteine residues of F protein were 76,199,338,347,362,370,394,399,401,424,514,523 amino acids,the neutral antigen sites of F protein were mutated at 72,75,79 and 170 amino acids,the amino acids of HN protein receptor binding site and NA active site were 174R,401E,416R,526Y,no mutation occurred.In this study,the whole gene sequence characteristics of Newcastle disease Class Ⅰ strain in laying hens in Yunnan Province were reported for the first time,which laid a foundation for the study of Newcastle disease virus Class Ⅰ strain.

Key words: Newcastle disease virus(NDV); high-throughput sequencing; Class Ⅰ; F gene; HN gene; phylogenetic analysis

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