title: Evolutionary Dynamics of a Highly Pathogenic Type 2 Porcine Reproductive and Respiratory Syndrome Virus: Analyses of Envelope Protein-Coding Genes.
abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) has long been an economically devastating swine viral disease. The recent emergence of a highly pathogenic type 2 PRRSV with high mobility and mortality in China, spreading in Vietnam, Laos, and Thailand has placed neighbouring countries at risk. This study applied a codon-based extension of the Bayesian relaxed clock model and the fixed effects maximum-likelihood method to investigate and compare the evolutionary dynamics of type 2 PRRSV for all of known structural envelope protein-coding genes. By comparing the highly pathogenic type 2 PRRSV clade against the typical type 2 PRRSV clade, this study demonstrated that the highly pathogenic clade evolved at high rates in all of the known structural genes but did not display rapid evolutionary dynamics compared with typical type 2 PRRSV. In contrast, the ORF3, ORF5 and ORF6 genes of the highly pathogenic clade evolved in a qualitatively different manner from the genes of the typical clade. At the population level, several codons of the sequence elements that were involved in viral neutralization, as well as codons that were associated with in vitro attenuation/over-attenuation, were predicted to be selected differentially between the typical clade and the highly pathogenic clade. The results of this study suggest that the multigenic factors of the envelope protein-coding genes contribute to diversifying the biological properties (virulence, antigenicity, etc.) of the highly pathogenic clade compared with the typical clade of type 2 PRRSV.
authors: Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea.|Department of Veterinary Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, Hanoi University of Agriculture, Hanoi, Vietnam.
authors: V G
authors: VG
authors: Nguyen
authors: Research Evaluation Team, Institute for Basic Science, Daejeon, Korea.
authors: H K
authors: HK
authors: Kim
authors: Research Unit, Green Cross Veterinary Products, Yongin, Korea.
authors: H J
authors: HJ
authors: Moon
authors: Viral Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea.
authors: S J
authors: SJ
authors: Park
authors: Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea.
authors: H C
authors: HC
authors: Chung
authors: Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea.
authors: M K
authors: MK
authors: Choi
authors: Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea.
authors: B K
authors: BK
authors: Park
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D002681:China; D003062:Codon; D019143:Evolution, Molecular; D016013:Likelihood Functions; D017720:Molecular Epidemiology; D010802:Phylogeny; D019318:Porcine Reproductive and Respiratory Syndrome / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics* / Q000472:pathogenicity; D013552:Swine; D014759:Viral Envelope Proteins / Q000235:genetics*
chemical_list: D003062:Codon; D014759:Viral Envelope Proteins
keywords: envelope protein-coding genes; evolutionary dynamics; highly pathogenic type 2 PRRSV