Lv Hongchao, Zhang Yanping, Sun Guorong, Bao Keyan, Gao Yulong, Qi Xiaole, Cui Hongyu, Wang Yongqiang, Li Kai, Gao Li, Pan Qing, Wang Xiaomei, Liu Changjun
Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, the Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
Infect Genet Evol. 2017 Jul;51:263-274. doi: 10.1016/j.meegid.2016.04.027. Epub 2016 Apr 22.
Gallid herpesvirus 2 (GaHV-2), which causes Marek's disease in chickens and has caused extensive economic losses, has recently evolved increased virulence in China. To better understand the genetic basis of the pathogenic characteristics changed and increased virulence, we sequenced the genomes of six new GaHV-2 strains (LCC, LTS, WC/1203, JL/1404, CC/1409, and HS/1412) isolated from chickens with failed immunisation as well as one previously isolated Chinese GaHV-2 strain, J-1. Based on a multiple sequence alignment, several characteristic point mutations were detected in the open reading frames of the Chinese isolates. In addition, two deletions and an insertion were identified at the unique short region and terminal repeat short region junctions in Chinese isolates, and the insertion was a characteristic of the new Chinese isolates. According to a phylogenetic analysis, the GaHV-2 genome diverged substantially over the last two decades in China. Based on the internal repeat long region, the new isolates were closely related to very virulent or very virulent plus strains. Additionally, the new Chinese isolates diverged from the previously isolated strains J-1 and 814. In conclusion, our results provide evidence that Chinese GaHV-2 strains contain characteristic sequences, especially the new isolates. The observed genetic divergence in the new Chinese GaHV-2 strains over the last two decades may be related to observed changes in pathogenic characteristics and virulence.
鸡疱疹病毒2型（GaHV - 2）可引发鸡的马立克氏病，已造成广泛的经济损失，最近在中国其毒力有所增强。为了更好地理解致病特性改变和毒力增强的遗传基础，我们对从免疫失败的鸡中分离出的6株新的GaHV - 2毒株（LCC、LTS、WC/1203、JL/1404、CC/1409和HS/1412）以及之前分离出的1株中国GaHV - 2毒株J - 1进行了基因组测序。基于多序列比对，在中国分离株的开放阅读框中检测到了几个特征性点突变。此外，在中国分离株的独特短区域和末端重复短区域连接处鉴定出两个缺失和一个插入，该插入是中国新分离株的特征。根据系统发育分析，在过去二十年中，中国的GaHV - 2基因组发生了显著分化。基于内部重复长区域，新分离株与超强毒或超强毒加毒株密切相关。此外，中国新分离株与之前分离的毒株J - 1和814有所不同。总之，我们的结果表明中国的GaHV - 2毒株含有特征性序列，尤其是新分离株。过去二十年中中国新的GaHV - 2毒株中观察到的遗传分化可能与观察到的致病特性和毒力变化有关。
