Fei Dongliang, Guo Yaxi, Fan Qiong, Wang Haoqi, Wu Jiadi, Li Ming, Ma Mingxiao
Institute of Biological Sciences, Jinzhou Medical University, Jinzhou, Liaoning, China.
College of Veterinary Medicine, Northeast Agricultural University, Haerbin, Heilongjiang, China.
PeerJ. 2019 Jun 28;7:e7214. doi: 10.7717/peerj.7214. eCollection 2019.
Deformed wing virus (DWV) is one of many viruses that infect honeybees and has been extensively studied because of its close association with honeybee colony collapse that is induced by . However, virus genotypes, sequence characteristics, and genetic variations of DWV remain unknown in China.
Two DWV strains were isolated from Jinzhou and Qinhuangdao cities in China, and were named China1-2017 (accession number: MF770715) and China2-2018 (accession number: MH165180), respectively, and their complete genome sequences were analyzed. To investigate the phylogenetic relationships of the DWV isolates, a phylogenetic tree of the complete open reading frame (ORF), structural protein VP1, and non-structural protein 3C+RdRp of the DWV sequences was constructed using the MEGA 5.0 software program. Then, the similarity and recombinant events of the DWV isolated strains were analyzed using recombination detection program (RDP4) software and genetic algorithm for recombination detection (GARD).
The complete genomic analysis showed that the genomes of the China1-2017 and China2-2018 DWV strains consisted of 10,141 base pairs (bp) and 10,105 bp, respectively, and contained a single, large ORF (China1-2017: 1,146-9,827 bp; China2-2018: 1,351-9,816 bp) that encoded 2,894 amino acids. The sequences were compared with 20 previously reported DWV sequences from different countries and with sequences of two closely related viruses, Kakugo virus (KV) and virus-1. Multiple sequence comparisons revealed a nucleotide identity of 84.3-96.7%, and identity of 94.7-98.6% in amino acids between the two isolate strains and 20 reference strains. The two novel isolates showed 96.7% nucleotide identity and 98.1% amino acid identity. The phylogenetic analyses showed that the two isolates belonged to DWV Type A and were closely related to the KV-2001 strain from Japan. Based on the RDP4 and GARD analyses, the recombination of the China2-2018 strain was located at the 4,266-7,507 nt region, with Korea I-2012 as an infer unknown parent and China-2017 as a minor parent, which spanned the entire helicase ORF. To the best of our knowledge, this is the first study to the complete sequence of DWV isolated from and the possible DWV recombination events in China. Our findings are important for further research of the phylogenetic relationship of DWVs in China with DWV strains from other countries and also contribute to the understanding of virological properties of these complex DWV recombinants.
变形翼病毒（DWV）是众多感染蜜蜂的病毒之一，因其与蜜蜂蜂群崩溃密切相关而受到广泛研究。然而，在中国，DWV的病毒基因型、序列特征和遗传变异情况仍不清楚。
从中国锦州和秦皇岛市分离出两株DWV毒株，分别命名为China1 - 2017（登录号：MF770715）和China2 - 2018（登录号：MH165180），并对其完整基因组序列进行分析。为研究DWV分离株的系统发育关系，使用MEGA 5.0软件程序构建了DWV序列的完整开放阅读框（ORF）、结构蛋白VP1和非结构蛋白3C + RdRp的系统发育树。然后，使用重组检测程序（RDP4）软件和重组检测遗传算法（GARD）分析DWV分离株的相似性和重组事件。
完整基因组分析表明，China1 - 2017和China2 - 2018 DWV毒株的基因组分别由10,141个碱基对（bp）和10,105 bp组成，包含一个单一的大ORF（China1 - 2017：1,146 - 9,827 bp；China2 - 2018：1,351 - 9,816 bp），编码2,894个氨基酸。将这些序列与之前报道的来自不同国家的20个DWV序列以及两种密切相关病毒——卡库戈病毒（KV）和[未提及病毒名称] - 1的序列进行比较。多序列比较显示，两株分离株与20个参考株之间的核苷酸同一性为84.3 - 96.7%，氨基酸同一性为94.7 - 98.6%。这两株新分离株的核苷酸同一性为96.7%，氨基酸同一性为98.1%。系统发育分析表明，这两株分离株属于A型DWV，与来自日本的KV - 2001毒株密切相关。基于RDP4和GARD分析，China2 - 2018毒株的重组位于4,266 - 7,507 nt区域，推断未知亲本为韩国I - 2012，次要亲本为China - 2017，该区域跨越整个解旋酶ORF。据我们所知，这是首次对从[未提及地点]分离的DWV完整序列及中国可能的DWV重组事件进行研究。我们的研究结果对于进一步研究中国DWV与其他国家DWV毒株的系统发育关系具有重要意义，也有助于理解这些复杂DWV重组体的病毒学特性。
