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Molecular Organization

Genome Organization, Genetic Characterization, and Proteins

The non-pathogenic PCV1 and the pathogenic PCV2 share less than 80% nucleotide sequence identity (Fenaux et al., 2000; Hamel et al., 1998; Meehan et al., 1998). The lengths of the genomic DNAs of the PCV1 isolates range from 1,758 to 1,760 bp (Fenaux et al., 2000). Sequence analyses of the complete genomesof PCV-2 isolates showed that the complete genome of each PCV2 isolate is 1,767 to 1,768 bp in length (Fenaux et al., 2000; Mankertz et al., 2000). Analysis and comparison of PCV2 isolates demonstrated that PCV2 isolates share 94.6-99.0% nucleotide sequence identities (de Boisséson et al., 2004; Fenaux et al., 2000). The two main viral genes are ORF1 and ORF2 which are oriented in opposite directions and which represent 93% of the PCV2 genome. ORF1 is associated with replication, it is highly conserved among isolates, and it encodes a protein of 35.7 kDa. (Mankertz et al., 1998). The ORF2 gene encodes for the 27.8 kDa capsid protein (Nawagitgul et al., 2000, 2002) and shares about 91-100% nucleotide sequence identity and about 90-100% amino acid sequence identity among PCV2 isolates (Fenaux et al. 2000; de Boisseson et al., 2004). In addition to ORF1 and ORF2, it is predicted that there are another four potential ORFs encoding proteins larger than 5kDa (Meehan et al., 1998). Recently, it has been shown that ORF3 protein is not essential for PCV2 replication in vitro but is involved in PCV2 induced apoptosis by activating caspase-8 and caspase-3 pathways (Liu et al., 2005)

References:
De Boisséson C, Béven V, Bigarré L, Thiéry R, Rose N, Eveno E, Madec F, Jestin A: Molecular characterization of porcine circovirus type 2 isolates from post-weaning multisystemic wasting syndrome-affected and non-affected pigs. J Gen Virol. 85:293-304, 2004

Fenaux M, Halbur PG, Gill M, Toth TE, Meng XJ: Genetic characterization of type 2 porcine circovirus (PCV-2) from pigs with postweaning multisystemic wasting syndrome in different geographic regions of North America and development of a differential PCR-restriction fragment length polymorphism assay to detect and differentiate between infections with PCV-1 and PCV-2. J Clin Microbiol. 38:2494-2503, 2000

Hamel AL, Lin LL, Nayar GPS: Nucleotide sequence of porcine circovirus associated with postweaning multisystemic wasting syndrome in pigs. J Virol. 72:5262-5267, 1998

Liu J, Chen I, Kwang J: Characterization of a previously unidentified viral protein in porcine circovirus type 2-infected cells and its role in virus-induced apoptosis. J Virol. 79:8262-8274, 2005

Mankertz A, Domingo M, Folch JM, LeCann P, Jestin A, Segalés J, Chmielewicz B, Plana-Durán J, Soike D: Characterisation of PCV-2 isolates from Spain, Germany and France. Virus Res. 66:65-77, 2000

Mankertz A, Mankertz J, Wolf K, Buhk HJ: Identification of a protein essential for replication of porcine circovirus. J Gen Virol. 79:381-384, 1998

Meehan BM, McNeilly F, Todd D, Kennedy S, Jewhurst VA, Ellis JA, Hassard LE, Clark EG, Haines DM, Allan GM: Characterization of novel circovirus DNAs associated with wasting syndromes in pigs. J Gen Virol. 79:2171-2179, 1998

Nawagitgul P, Harms PA, Morozov I, Thacker BJ, Sorden SD, Lekcharoensuk C, Paul PS: Modified indirect porcine circovirus (PCV) type 2-based and recombinant capsid protein (ORF2)-based enzyme-linked immunosorbent assays for detection of antibodies to PCV. Clin Diagn Lab Immunol. 9:33-40, 2002

Nawagitgul P, Morozov I, Bolin SR, Harms PA, Sorden SD, Paul PS: Open reading frame 2 of porcine circovirus type 2 encodes a major capsid protein. J Gen Virol. 81:2281-2287, 2000

Molecular Organization

Replication and Binding Strategy

 

PCV2

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Research

Control

Diagnosis

Factors

PCVAD

Molecular Organization

Pathogenesis

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Epidemiology

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