2014-2018年我国5株基因Ⅶ型新城疫病毒的基因组特性

Genomic Characteristics of Five Strains of Genotype Ⅶ Newcastle Disease Viruses Isolated in China from 2014 to 2018

为了解我国基因Ⅶ型新城疫病毒的分子生物学特性,对2014-2018年分离的5株基因Ⅶ型新城疫病毒代表株进行了基因组测序和生物信息学分析。序列分析显示:5株病毒F蛋白裂解位点为112RRQKR/F117或112RRRKR/F117,具有强毒株的典型特征;病毒基因组长度均为15 192 nt,其F蛋白融合肽、七肽重复区和跨膜区,以及HN蛋白跨膜区、中和抗原表位等功能区有多处氨基酸变异。病毒F基因遗传进化分析显示:2014-2015年分离的2株病毒属于基因Ⅶ.1.1亚型;2016-2018年分离的3株病毒属于基因Ⅶ.2亚型,暗示此亚型毒株可能已逐步取代基因Ⅶ.1.1亚型,成为家禽中的优势流行毒株。本研究进一步掌握了我国基因Ⅶ型新城疫病毒的遗传特性,从而为科学防控该病提供了参考。

In order to recognize the molecular biological characteristics of genotype Ⅶ Newcastle disease virus(NDV)in China,five strains of representative genotype Ⅶ NDVs isolated from 2014 to 2018 were sequenced and analyzed. It was found that the cleavage site of F protein of the five isolates was 112 RRQKR/F117 or 112 RRRKR/F117,with the typical characteristics of virulent strain;the complete length of virus genome was 15 192 nt,and several amino acid mutations were identified in the fusion peptide,heptad repeat region and transmembrane domain of F protein,and the transmembrane domain and neutralizing epitope of HN protein. Analysis on genetic evolution of F genes showed that,the two strains isolated from 2014 to 2015 belonged to sub-genotype Ⅶ.1.1,and other three isolated from 2016 to 2018 fell into sub-genotype Ⅶ.2,which might gradually replace the sub-genotype Ⅶ.1.1 and become dominant in poultry. In short,the genetic characteristics of NDV genotype Ⅶ were identified,which provided some references for scientific prevention and control of Newcastle disease.