Fig 1.

Schematic organization of parental and chimeric PRRSV and EAV genomes. The genomic organizations of the parental viruses, vEAV030 and vAPRRS, are represented using filled and open rectangles, respectively. The intermediate construct vAPRRSasc was generated by inserting an AscI restriction enzyme recognition sequence (ggcgcgcc) between the ORF1b stop codon and the ORF2a start codon. Next, the minor envelope protein-coding region of vAPRRSasc, ORF2a to ORF4, was replaced with the corresponding gene set of vEAV030, and the resultant chimeric virus was designated vAPRRS-EAV2ab34. The nucleotide sequences flanking the swapped ORFs of the chimera are shown within dashed boxes (with vAPRRS sequences in lowercase and vEAV030 sequences in uppercase).