Fig. 1.

Design of the recombinant plasmids. (A) The basic structure of plasmid pLRII. (B) ORF5 gene was cloned into pLRII (named as pLR-ORF5) that was used to express GP5 of PRRSV. (C) ORF6 gene was cloned into pLRII (pLR-ORF6) that were used to express M of PRRSV. (D) GP5 and M were expressed as a fusion protein under the control of the same promoter (Psyn). (E) GP5 and M were expressed separately under the control of two different promoters (Psyn and VP7.5). Psyn, the synthesized strong early/late compound promoter; VP7.5, the late/early promoter of vaccine virus; TTTTTAT, the transcription termination signal sequence; ORF5, ORF5 gene of PRRSV; ORF6, ORF6 gene of PRRSV; DeletionII, the deletion II region of MVA genome