﻿Genome Sequence of a Reassortant H5N1 Avian Influenza Virus
Isolated from Domestic Green-Winged Teal
Chaochao Xiong, Qian Liu, Quanjiao Chen, Jianjun Chen
Center for Emerging Infectious Diseases, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei, China
An avian influenza virus strain, A/domestic green-winged teal/Hunan/3450/2006(H5N1) (DGW-T3450), was isolated from do-
mestic green-winged teals. Genome analysis demonstrated that DGW-T3450 is a novel reassortant strain. The hemagglutinin
(HA) and neuraminidase (NA) genes of this strain originated from H5N1 viruses circulating in poultry, while its remaining
genes are derived from multiple ancestors, including viruses like those that infect wild birds.
Received 18 July 2013 Accepted 22 July 2013 Published 15 August 2013
Citation Xiong C, Liu Q, Chen Q, Chen J. 2013. Genome sequence of a reassortant H5N1 avian influenza virus isolated from domestic green-winged teal. Genome Announc.
1(4):e00639-13. doi:10.1128/genomeA.00639-13.
Copyright © 2013 Xiong et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 Unported license.
Address correspondence to Jianjun Chen, chenjj126@126.com.
H5N1 highly pathogenic avian influenza (HPAI) viruses have
seriously affected the Asian poultry industry since their re-
currence in 2003. In a previous study, we isolated two H5N1 viral
strains, closely related to viruses circulating in chickens and ducks,
from apparently healthy domestic green-winged teals (1). These
results suggested that domestic green-winged teals, a type of wild
duck bred for meat, may play an important role in the transmis-
sion of avian influenza virus.
In this study, an H5N1 virus, designated A/domestic green-
winged teal/Hunan/3450/2006 (DGW-T3450), was isolated from
domestic green-winged teals. We carried out reverse transcription
(RT)-PCR using universal primers for influenza A virus and se-
quenced the entire viral genome (2). The full lengths of the gene
segments are as follows: hemagglutinin (HA) gene, 1,776 nucleo-
tides (nt); neuraminidase (NA) gene, 1,398 nt; nucleoprotein
(NP) gene, 1,565 nt; polymerase PB1 and PB2 genes, 2,341 nt each;
polymerase acidic protein (PA) gene, 2,233 nt; matrix (M) gene,
1,027 nt; and nonstructural (NS) protein gene, 890 nt.
Sequence analysis revealed that the nucleotide sequence of the
HA gene of DGW-T3450 is homologous to that of the already
identified strain A/environment/Hunan/1-8/2007(H5N1), shar-
ing 99% nucleotide homology, while the NA gene sequence
is most closely related to that of A/chicken/Sichuan/81/
2005(H5N1). The NP gene nucleotide sequence shares approxi-
mately 98% identity with that of H8N4 A/duck/Yangzhou/02/
2005(H8N4). The PB1 and PB2 gene fragments are most closely
related to H6N2 isolate A/duck/Guizhou/2773/2006(H6N2) and
H6N2 isolate A/duck/Guizhou/1088/2007(H6N2), respectively,
with both sharing 99% nucleotide identity. The PA and M genes
share the greatest DNA sequence identities (over 99%) with H7N7
isolate A/mallard/Korea/GH170/2007(H7N7) and H3N6 isolate
A/red crested pochard/Mongolia/1915/2006(H3N6), respec-
tively. The NS gene nucleotide sequence is 99% similar to that of
the H3N1 isolate A/whooper swan/Mongolia/1-21/2007(H3N1).
These results indicate that the DGW-T3450 virus is a novel reas-
sortant H5N1 virus, with its HA and NA genes derived from H5N1
viruses circulating in poultry and its remaining genes originating
from multiple ancestors, including viruses like those that infect
wild birds.
Based on the deduced amino acid sequence of the HA gene,
DGW-T3450 possesses multiple basic amino acids at the connect-
ing peptide between HA1 and HA2 (RRRGKR/G), a signal of high
pathogenicity in chickens (3). The receptor-binding pocket re-
tains the amino acid residues 222Gln and 224Gly in HA1, indicat-
ing an 2,3-linked sialic acid preference and a greater likelihood of
avian infectivity (1, 4). No 627Lys or 701Asn mutations, which are
associated with high virulence in mice (5, 6), are found in PB2. In
addition, no 5-amino-acid (aa) deletion is present in the middle of
the NS protein as in the dominant H5N1 found in southern
China. The absence of an His274Tyr mutation in the DGW-T3450
NA protein indicates that DGW-T3450 may be sensitive to neur-
aminidase inhibitors (7).
In summary, DGW-T3450 is a novel reassortant avian influ-
enza virus with its gene constellation derived from multiple an-
cestors, including viruses like those that infect wild birds. These
results highlight the importance of surveillance at live poultry
markets.
Nucleotide sequence accession numbers. The genome se-
quences of A/domestic green-winged teal/Hunan/3450/2006(H5N1)
have been deposited in GenBank under accession num-
bers KC690153 to KC690160.
ACKNOWLEDGMENTS
This study was supported by the following research funds: National 973
Project (2010CB530301); National Natural Science Foundation of China
(310000088); Foundation for Study Encouragement to Young Scien-
tists, Chinese Academy of Sciences (KSCX2-EW-J-19); and the Ministry
of Science and Technology Special Project (2013FY113500).
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