title: Quasispecies evolution of the prototypical genotype 1 porcine reproductive and respiratory syndrome virus early during in vivo infection is rapid and tissue specific.
abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) is a major infectious threat to the pig industry worldwide. Increasing evidence suggests that microevolution within a quasispecies population can give rise to high sequence heterogeneity in PRRSV; potentially impacting the pathogenicity of the virus. Here, we report on micro-evolutionary events taking place within the viral quasispecies population in lung and lymph node 3 days post infection (dpi) following experimental in vivo infection with the prototypical Lelystad PRRSV (LV). Sequence analysis revealed 16 high frequency single nucleotide variants (SNV) or differences from the reference LV genome which are assumed to be representative of the consensus inoculum genome. Additionally, 49 other low frequency SNVs were also found in the inoculum population. At 3 dpi, a total of 9 and 10 SNVs of varying frequencies could already be detected in the LV population infecting the lung and lymph nodes, respectively. Interestingly, of these, three and four novel SNVs emerged independently in the two respective tissues when compared to the inoculum. The remaining variants, though already present at lower frequencies in the inoculum, were positively selected and their frequency increased within the quasispecies population. Hence, we were able to determine directly from tissues infected with PRRSV the repertoire of genetic variants within the viral quasispecies population. Our data also suggest that microevolution of these variants is rapid and some may be tissue-specific.
authors.affiliation: PAPRSB Institute of Health Sciences, Universiti Brunei Darussalam, Bandar Seri Begawan, Brunei.|The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK.
authors.forename: Zen H
authors.initials: ZH
authors.lastname: Lu
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK.|Northwest A&F University, Xianyang, China.
authors.forename: Xinglong
authors.initials: X
authors.lastname: Wang
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK.
authors.forename: Alison D
authors.initials: AD
authors.lastname: Wilson
authors.affiliation: Animal and Plant Health Agency, Preston, UK.
authors.forename: Daniel L W
authors.initials: DLW
authors.lastname: Dorey-Robinson
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK.
authors.forename: Alan L
authors.initials: AL
authors.lastname: Archibald
authors.affiliation: The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK. tahar.aitali@roslin.ed.ac.uk.
authors.forename: Tahar
authors.initials: T
authors.lastname: Ait-Ali
authors.affiliation: Animal and Plant Health Agency, Preston, UK.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Frossard
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D014644:Genetic Variation; D005838:Genotype; D008168:Lung / Q000821:virology; D008198:Lymph Nodes / Q000821:virology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics* / Q000302:isolation & purification; D013552:Swine / Q000821:virology*