Figure 5From: A 5'-proximal Stem-loop Structure of 5' Untranslated Region of Porcine Reproductive and Respiratory Syndrome Virus Genome Is Key for Virus ReplicationStructural protein expression and phenotypic properties of the stem deletion mutant viruses. (A) Intracellular N protein expression of WT and mutant viruses. BHK-21 cells were transfected with plasmids of WT and mutants D1-D6 as indicated in Figure 3. Expression of N protein was visualized by immunofluorescence staining at 24 hours post-transfection. (B) Viral plaque morphology and growth curves of the mutant viruses D1-D6 as described in Figure 3.Back to article page