Fig. 1

Schematic diagrams of distinct strategies for rPRV generation. A Generation of rPRV by homologous recombination technology. The recombinant plasmids are transfected into cells and then infected with PRV. Subsequently, rPRV with fluorescent expression cassette is isolated and purified by plaque assay. B Generation of rPRV by BAC system. The recombinant transfer plasmids and PRV genome are co-transfected into cells to generate the PRV-BAC vector. Then PRV-BAC vector is transfected into cells to produce recombinant virus. C Generation of rPRV by CRISPR/Cas9 technology. a CRISPR/Cas9-gRNA plasmids and donor plasmids containing target gene sequences and fluorescent expression cassettes are co-transfected into cells for 24 h and infected with PRV for 24 h. rPRV with fluorescent expression cassette is then isolated and purified by plaque assay. b CRISPR/Cas9-gRNA plasmids and PRV genome are co-transfected into cells, and rPRV is then isolated and purified by plaque assay. Recombinant viruses are then verified by PCR and sequencing