Effects of deletion of the early protein 0 gene of pseudorabies virus on the overall viral gene expression.

Real-time RT-PCR analysis was applied to evaluate the impact of deletion of the early protein 0 (EP0) gene of pseudorabies virus (PRV) on the global expression of the viral transcripts during lytic infection in cultured porcine kidney cells. Our analysis showed that EP0 exerted an inhibitory effect on the transcription of the PRV genes in the early stage of infection, and alternating stimulatory and inhibitory effects on the viral gene expressions in the late stage of infection. The data also suggested that a general function of EP0 might be to reverse the kinetics of expression of early viral genes. We also observed that EP0 facilitated the development of correlations in the transcription kinetics between the immediate early 180 gene and the PRV transcripts, indicating that a major function of EP0 could be to modify the effects of the IE180 protein on the PRV transcriptome.