1 Zimmerman J J, Yoon K J,Wills RW,et al. General over-view of PRRSV:a perspecaive from the United States[J]. Microbio1,1997,55(1-4):187-196
[2]
2 Rossow K D. Porcine reproducaive and respiratory syn-drome[J]. Vet Pathol,1998, 35:1-20
[3]
3 Kelfaver K K. Reproducaive failure of unknown etiology[J]. Am Assoc Swine Praca News，1989，1(2):1-9
[4]
4 Nelsen C J, Murtaugh M P, Faaberg K S. Porcine repro-ducaive and respiratory syndrome virus comparison:diver-gent evolution on two continents[J]J Virol, 1999，73(1):270-80.
[5]
5 Meulenberg J J,de Meijer E J,Moormann R J. Subgenom-ic RNAs of Lelystad virus。ontain a conserved leader-body juncaion sequence[J].J Gen Viro1,1993,74(8):1697-1701
[6]
6 Stadejek T, Oleksiewicz M B，Potapc:huk D, et al. Porcine reproducaive and respiratory syndrome virus strains of ex-ceptional diversity in eastern Europe support the definition of new genetic: subtypes [J]. J Gen Virol,2006, 87 (Pt7): 1835-1841
15 Den Boon J A,Faaherg K S,Meulenherg J J, et al. Pro-cessing and evolution of the N-terminal region of the ar-terivirus replicase ORFla protein:identification of twoPapainlike cysteine proteases[J]. Virol, 1995，69(7):4500-4505
[10]
16 Li Y,Wang X,Bo K,et al. Emergence of a highly patho-genic porcine reproducaive and respiratory syndrome vi-rus in the Mid-Eastern region of China[J]. Vet J,2007，174(3);577-584
[11]
17 Zhou L,Zhang J,Zeng J,et al. The 30-amino-acid deletionin the Nsp2 of high1y pathogenic: porcine reproducaive and respiratory syndrome virus emerging in China is not relat-ed to its virulence[J]I Virol, 2009，83(10):5156-5157
[12]
7 Collins J E，Benfield D A, Christianson WT, et al. Isola-tion of swine infertility and respiratory syndrome virus (i-solute ATCC VR-2332) in North America and experimen-tal reproducaion of the disease in gnotobiotic pigs[J].J Vet Diagn,1992,4(2):117-126
10 Tian K G, Yu X L, Zhao T Z，et al. Emergence of fatal PRRSV variants:unparalleled outbreaks of atypical PRRS in China and molecular dissecaion of the unique hallmark[J]. P1oS ONE,2007,2(6);526-539
[16]
11 Tong G Z, Zhou Y J, Hao X F, et al. Highly pathogenic porcine reproducaive and respiratory syndrome, China [J].Emerging Infecioust Diseases,2007，13(9):1434-1436
[17]
12 Zhou L, Yang H C. Porcine reproducaive and respiratory syndrome in China[J]. Virus Res,2010，154(1-2):31-37
[18]
18 Zhou Y J, Yu H, Tian Z J, et al. Genetic: diversity of theORFS gene of porcine reproducaive and respiratory syn-drome virus isolates in China from 2006 to 2008[J]Virus Res,2009，144(1-2):136-144
[19]
19 Yin G, Gan L, Shu X, et al. Genetic: diversity of theORFS gene of porcine reproducaive and respiratory syn-drome virus isolates in southwest China from 2007 to2009[J]. Plos One,2012,7(3):e33756
[20]
20 Wei X,Decker J M，Wang S,et al. Antibody neutraliza-tion and escape by HIV-1[J]Nature, 2003，422(6929);307-312
[21]
21 Han J,Wang Y,Faaberg K S. Complete genome analysisof RFLP 184 isolates of porcine reproducaive and respira-tort'' syndrome virus[J]. Virus Res,2006，122(1-2):175-182.
