Genetic diversity of the VP1 gene of duck hepatitis virus type I (DHV-I) isolates from southeast China is related to isolate attenuation.
The complete sequence of an isolate (ZJ-V) of Duck hepatitis virus I (DHV-I), originally taken from the field in southeast China was determined. It was 7691 nucleotides long and had 5'- and 3'-terminal non-coding regions of 626 and 315 nucleotides, respectively. The poly(A) tail contained at least 22 residues and the single open reading frame encoded a polypeptide of 2249 amino acids. The VP1 gene was also sequenced from nine southeast China field isolates and three attenuated DHV-I vaccine strains. In phylogenetic analysis of the isolates and other published sequences, attenuated and tissue-adapted isolates (including ZJ-V) clustered as genotypes significantly different from the field isolates that had not been passaged in chicken/duck embryos. There were two consistent amino acid substitutions (E(129)-->V(129) and A(142)-->S(142)) between all the field isolates and all the tissue-adapted ones. The carboxyl terminal region was generally the most variable and here the four attenuated Chinese isolates showed six consistent differences from the field isolates (S(181)-->L(181), H(183)K(184)-->R(183)G(1841), N(193)-->D(193), E(205)-->K(205), R(217)-->K(217), N(235)-->D(235)). It seems likely that at least some of these differences result from mutations leading to isolate attenuation.
Liu
Guangqing
G
Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou, People's Republic of China.
Wang
Fei
F
Ni
Zheng
Z
Yun
Tao
T
Yu
Bin
B
Huang
Jionggang
J
Chen
Jianping
J
D000595:Amino Acid Sequence; D000818:Animals; D002642:Chick Embryo; D004372:Ducks; D014644:Genetic Variation; D016679:Genome, Viral / Q000235:genetics; D004371:Hepatitis Virus, Duck / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D006524:Hepatitis, Viral, Animal / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010850:Picornaviridae Infections / Q000662:veterinary* / Q000821:virology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014613:Vaccines, Attenuated / Q000235:genetics; D014758:Viral Core Proteins / Q000737:chemistry / Q000235:genetics*; D014774:Virulence / Q000235:genetics
D014613:Vaccines, Attenuated; D014758:Viral Core Proteins