phaidra.vetmeduni.ac.at o:1394 DOI 10.3390/v15010258 A Conserved Stem-Loop Structure within ORF5 Is a Frequent Recombination Hotspot for Porcine Reproductive and Respiratory Syndrome Virus 1 (PRRSV-1) with a Particular Modified Live Virus (MLV) Strain The emergence of recombinant PRRSV strains has been observed for more than a decade. These recombinant viruses are characterized by a genome that contains genetic material from at least two different parental strains. Due to the advanced sequencing techniques and a growing number of data bank entries, the role of PRRSV recombinants has become increasingly important since they are sometimes associated with clinical outbreaks. Chimeric viruses observed more recently are products of PRRSV wild-type and vaccine strains. Here, we report on three PRRSV-1 isolates from geographically distant farms with differing clinical manifestations. A sequencing and recombination analysis revealed that these strains are crossovers between different wild-type strains and the same modified live virus vaccine strain. Interestingly, the recombination breakpoint of all analyzed isolates appears at the beginning of open reading frame 5 (ORF5). RNA structure predictions indicate a conserved stem loop in close proximity to the recombination hotspot, which is a plausible cause of a polymerase template switch during RNA replication. Further research into the mechanisms of the stem loop is needed to help understand the PRRSV recombination process and the role of MLVs as parental strains. eng Stem Loop ORF5 Modified Live Virus Vaccine Recombinant Virus Recombination Arteriviridae PRRSV Porcine Reproductive And Respiratory Syndrome Virus 2023-03-08T16:11:51.604Z LOMv1.0 Author BEGIN:VCARD VERSION:3.0 N:Mötz;Marlene; FN:Marlene Mötz X-ORCID:https://orcid.org/0000-0001-7929-5662 END:VCARD BEGIN:VCARD VERSION:3.0 N:Rümenapf;Till; FN:Till Rümenapf X-ORCID:https://orcid.org/0000-0002-2951-7471 END:VCARD BEGIN:VCARD VERSION:3.0 N:Riedel;Christiane; FN:Christiane Riedel X-ORCID:https://orcid.org/0000-0002-4349-996X END:VCARD BEGIN:VCARD VERSION:3.0 N:Auer;Angelika; FN:Angelika Auer X-ORCID:https://orcid.org/0000-0002-4790-9823 END:VCARD BEGIN:VCARD VERSION:3.0 N:Lamp;Benjamin; FN:Benjamin Lamp X-ORCID:https://orcid.org/0000-0002-9668-1896 END:VCARD BEGIN:VCARD VERSION:3.0 N:Ladinig;Andrea; FN:Andrea Ladinig X-ORCID:https://orcid.org/0000-0001-5037-7269 END:VCARD BEGIN:VCARD VERSION:3.0 N:Stadler;Julia; FN:Julia Stadler END:VCARD BEGIN:VCARD VERSION:3.0 N:Kreutzmann;Heinrich; FN:Heinrich Kreutzmann X-ORCID:https://orcid.org/0000-0002-6010-697X END:VCARD https://w3id.org/kim/hcrt/scheme https://w3id.org/kim/hcrt/text Textdokument Text LOMv1.0 yes https://creativecommons.org/licenses/by/4.0 application/pdf 616885 https://phaidra.vetmeduni.ac.at/o:1394 https://phaidra.vetmeduni.ac.at/api/object/o:1394/thumbnail LOMv1.0 discipline