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Molecular analysis of the ORFs 3 to 7 of porcine reproductive and respiratory syndrome virus, Québec reference strain


The cDNA sequence of the 3′-terminal genomic region of the Québec IAF-exp91 strain of porcine reproductive and respiratory syndrome virus (PRRSV) was determined and compared to those of other reference strains from Europe (Lelystad virus) and US (ATCC VR2385, MN-1b). The sequence (2834 nucleotides) which encompassed ORFs 3 to 7 revealed extensive genomic variations between the Québec strain and Lelystad virus (LV), resulting from high number of base substitutions, additions and deletions. The ORFs 5, 3, and 7 seemed to be relatively the most variable; the predicted encoding products of the Québec and LV strains displayed only 52%, 54%, and 59% amino acid identities, respectively. Nevertheless, in vitro translation experiments of the structural genes (ORFs 5, 6, and 7) and radio-immunoprecipitation assays with extracellular virions gave results similar to those previously reported for LV. In contrast, close genomic relationships were demonstrated between Québec and US strains. Taking together, these results indicate that, although structurally similar, North American PRRSV strains belong to a genotype distinct from that of the LV, thus supporting previous findings that allowed to divide PRRSV isolates into two antigenic subgroups (U.S. and European).


  1. 1.

    Benfield DA, Nelson E, Collins JE, Harris L, Goyal SM, Robinson D, Christianson WT, Morrison RB, Gorcyca D, Chladek D (1992) Characterization of swine infertility and respiratory syndrome (SIRS) virus (isolate ATCC VR-2332). J Vet Diagn Invest 4: 127–133

    Google Scholar 

  2. 2.

    Chen Z, Kuo L, Rowland RRR, Even C, Faaberg KS, Plagemann GW (1993) Sequence of 3′ end of genome and of 5′ end of open reading frame la of lactate dehydrogenase-elevating virus and common junction motifs between 5′ leader and bodies of seven subgenomic mRNAs. J Gen Virol 74: 643–660

    Google Scholar 

  3. 3.

    Chirnside ED, Wearing CM, Binns MM, Mumford JA (1994) Comparison of M and N gene sequences distinguishes variation amongst equine arteritis virus isolates. J Gen Virol 75: 1491–1497

    Google Scholar 

  4. 4.

    Chomczynsky P, Sacchi N (1987) Single-step method of RNA isolation by acid guanidium thiocyanate phenol-chloroform extraction. Anal Biochem 162: 156–159

    Google Scholar 

  5. 5.

    Collins JE, Benfield DA, Christianson WT, Harris L, Hennings JC, Shaw DP, Goyal SM, McCullough S, Morrison RB, Joo HS, Gorcyca D, Chladek D (1992) Isolation of swine infertility and respiratory syndrome virus (isolate ATCC VR-2332) in North America and experimental reproduction of the disease in gnotobiotic pigs. J Vet Diagn Invest 4: 117–126

    Google Scholar 

  6. 6.

    Conzelmann KK, Visser N, Van Woensel P, Thiel HJ (1993) Molecular characterization of porcine reproductive and respiratory syndrome virus, a member of the arterivirus group. Virology 193: 329–339

    Google Scholar 

  7. 7.

    Dea S, Bilodeau R, Athanassious R, Sauvageau R, Martineau GP (1992) Swine reproductive and respiratory syndrome in Québec: isolation of an enveloped virus serologically-related to Lelystad virus. Can Vet J 33: 801–808

    Google Scholar 

  8. 8.

    Den Boon JA, Snijder EJ, Chirnside ED, De Vries AAF, Horzinek MC, Spaan WJM (1991) Equine arteritis virus is not a togavirus but belongs to the coronavirus-like superfamily. J Virol 65: 2910–2920

    Google Scholar 

  9. 9.

    De Vries AAF, Chirnside ED, Horzinek MC, Rottier JM (1992) Structural proteins of equine arteritis virus. J Virol 66: 6294–6303

    Google Scholar 

  10. 10.

    Godeny EK, Chen L, Kumar SN, Methven SL, Koonin EV, Brinton MA (1993) Complete genomic sequence and phylogenetic analysis of the lactate dehydrogenase-elevating virus (LDV). Virology 194: 585–596

    Google Scholar 

  11. 11.

    Goldbach R, Wellink J (1988) Evolution of plus-strand RNA viruses. Intervirology 29: 260–267

    Google Scholar 

  12. 12.

    Goyal SM (1993) Porcine reproductive and respiratory syndrome. J Vet Diagn Invest 5: 656–664

    Google Scholar 

  13. 13.

    Hooper CC, Van Alstine GW, Stevenson W, Kanitz CL (1994) Mice and rats (laboratory and feral) are not a reservoir for PRRS virus. J Vet Diagn Invest 6: 13–15

    Google Scholar 

  14. 14.

    Kim HS, Kwang J, Yoon IJ, Joo HS, Frey ML (1993) Enhanced replication of porcine reproductive and respiratory syndrome (PRRS) virus in a homogeneous subpopulation of MA-104 cell line. Arch Virol 133: 477–483

    Google Scholar 

  15. 15.

    Kwang J, Kim HS, Joo HS (1994) Cloning expression, and sequence analysis of the ORF 4 gene of the porcine reproductive and respiratory syndrome virus MN-1b. J Vet Diagn Invest 6: 293–296

    Google Scholar 

  16. 16.

    Lai MMC (1992) RNA recombination in animal and plant viruses. Microbiol Rev 56: 61–79

    Google Scholar 

  17. 17.

    Mardassi H, Athanassious R, Mounir S, Dea S (1994) Porcine reproductive and respiratory syndrome virus: morphological, biochemical and serological characteristics of Québec isolates associated to acute and chronic outbreaks of PRRS. Can J Vet Res 58: 55–64

    Google Scholar 

  18. 18.

    Mardassi H, Mounir S, Dea S (1994) Identification of major differences in the nucleocapsid protein genes of a Québec strain and European strains of porcine reproductive and respiratory syndrome virus. J Gen Virol 75: 681–685

    Google Scholar 

  19. 19.

    Mardassi H, Wilson L, Mounir S, Dea S (1994) Detection of porcine reproductive and respiratory syndrome virus and efficient differentiation between Canadian and European strains by reverse transcription and PCR amplification. J Clin Microbiol 32: 2197–2203

    Google Scholar 

  20. 20.

    Meng XJ, Paul PS, Halbur PG (1994) Molecular cloning and nucleotide sequencing of the 3′-terminal genomic RNA of the porcine reproductive and respiratory syndrome virus. J Gen Virol 75: 1795–1801

    Google Scholar 

  21. 21.

    Meulenberg JJM, Hulst MM, De Meijer EJ, Moonen PLJM, Den Besten A, De Kluyer EP, Wensvoort G, Moormann RJM (1993) Lelystad virus, the causative agent of porcine epidemic abortion and respiratory syndrome (PEARS), is related to LDV and EAV. Virology 192: 62–72

    Google Scholar 

  22. 22.

    Meulenberg JJM, De Meijer EJ, Moormann RJM (1993) Subgenomic RNAs of Lelystad virus contain a conserved leader-body junction sequence. J Gen Virol 74: 1697–1701

    Google Scholar 

  23. 23.

    Meulenberg JJM, Den Besten AP, De Kluyer EP, Moormann RJM, Schaaper VMM, Wensvoort G (1995) Characterization of proteins encoded by ORFs 2 to 7 of Lelystad virus. Virology 206: 155–163

    Google Scholar 

  24. 24.

    Murphy TW, McCollum WH, Timoney PJ, Klingeborn BW, Hyllseth B, Golnik W, Erasmus B (1992) Genomic variability among globally distributed isolates of equine arteritis virus. Vet Microbiol 32: 101–115

    Google Scholar 

  25. 25.

    Nelson EA, Hennings JC, Drew T, Wensvoort G, Collins JE, Benfield DE (1993) Differentiation of US and european isolates of porcine reproductive and respiratory syndrome virus by monoclonal antibodies. J Clin Microbiol 31: 3184–3189

    Google Scholar 

  26. 26.

    Plagemann PGW, Moening V (1992) Lactate dehydrogenase-elevating virus, equine arteritis virus, and simian hemorrhagic fever virus: a new group of positive-strand RNA viruses. Adv Virus Res 41: 99–192

    Google Scholar 

  27. 27.

    Sambrook J, Fritsch EF, Maniatis T (1989) Molecular cloning: A laboratory manual, 2nd ed. Cold Spring Harbor Laboratory Press, New York

    Google Scholar 

  28. 28.

    Sanger F, Nicklen S, Coulson AR (1977) DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci USA 74: 5463–5467

    Google Scholar 

  29. 29.

    Strauss JH, Strauss EG (1988) Evolution of RNA viruses. Annu Rev Microbiol 42: 657–683

    Google Scholar 

  30. 30.

    Suarez P, Zardoya R, Prieto C, Solana A, Tabares E, Bautista JM, Castro JM (1994) Direct detection of porcine reproductive and respiratory syndrome (PRRS) virus by reverse polymerase chain reaction (RT-PCR). Arch Virol 135: 89–99

    Google Scholar 

  31. 31.

    Von Heijne G (1986) A new method for predicting signal sequence cleavage sites. Nucleic Acids Res 14: 4683–4690

    Google Scholar 

  32. 32.

    Wensvoort G, De Kluyver EP, Luijtze EA, Den Besten A, Harris L, Collins JE, Christianson WT, Chladek D (1992) Antigenic comparison of Lelystad virus and swine and respiratory syndrome (SIRS) virus. J Vet Diagn Invest 4: 134–138

    Google Scholar 

  33. 33.

    Wensvoort G, De Kluyver EP, Pol JMA, Wagenaar F, Moormann RJM, Hulst MM, Bloemraad R, Den Besten A, Zetstra T, Terpstra C (1992) Lelystad virus, the cause of porcine epidemic abortion and respiratory syndrome: a review of mystery swine disease research at Lelystad. Vet Microbiol 33: 185–193

    Google Scholar 

  34. 34.

    Wensvoort G, Terpstra C, Pol JMA, Ter Laak EA, Bloemraad M, De Kluyver EP, Kragten C, Van Buiten L, Den Besten A, Wagenaar F, Broekhuijsen JM, Moonen PLJM, Zetstra T, De Boer EA, Tibben HJ, Dejong MF, Van't Veld P, Groenland GJR, Van Gennep JA, Voets MT, Verheijden JHM, Braamskamp J (1991) Mystery swine disease in the Netherlands: the isolation of Lelystad virus. Vet Q 13: 121–130

    Google Scholar 

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The nucleotide sequence data reported in this paper will appear in the EMBL and GenBank nucleotide sequence databases under accession number L40898.

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Mardassi, H., Mounir, S. & Dea, S. Molecular analysis of the ORFs 3 to 7 of porcine reproductive and respiratory syndrome virus, Québec reference strain. Archives of Virology 140, 1405–1418 (1995).

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  • Reference Strain
  • Amino Acid Identity
  • Genomic Variation
  • Acid Identity
  • Base Substitution