Figure 1From: Construction and in vitro evaluation of a recombinant live attenuated PRRSV expressing GM-CSFConstruction of the plasmid HuN4-GM-CSF. Porcine GM-CSF and a copy of the transcription regulatory sequence for PRRSV ORF6 (TRS6) were inserted between ORF1b and ORF2 of the infectious molecular clone of the HuN4-F112 vaccine strain by overlap PCR.Back to article page