Two full-length porcine reproductive and respiratory syndrome virus (PRRSV) genomes, strain VR-2332 and its cell culture passaged descendent RespPRRS vaccine strain, were compared and analyzed in order to identify possible sites of attenuation. Of the 44 nucleotide changes, 13 resulted in conservative changes and 18 produced non-conservative changes. The results suggest that key amino acids in ORF1 may contribute to the phenotype of RespPRRS, which includes increased growth rate on MA-104 cells and decreased virulence in swine. The results provide a genetic basis for future manipulation of a PRRSV reverse genetics system.
Bibliographical noteFunding Information:
The authors wish to thank Chris Nelsen and Faith Klebs for excellent technical expertise. Boehringer Ingelheim Vetmedica, Inc., provided financial support for the research.
- Genome comparison
- Porcine reproductive and respiratory syndrome virus (PRRSV)