Genomic analyses reveal that partial sequence of an earlier pseudorabies virus in China is originated from a Bartha-vaccine-like strain

• The PRV strains present a relatively large diversity.
• This diversity is related to geographical distribution of PRV strains around world.
• Partial genome of an earlier Chinese PRV derives from Bartha-vaccine-like strain.

Pseudorabies virus (PRV), the causative agent of Aujeszky׳s disease, has gained increased attention in China in recent years as a result of the outbreak of emergent pseudorabies. Several genomic and partial sequences are available for Chinese emergent and European–American strains of PRV, but limited sequence data exist for the earlier Chinese strains. In this study, we determined the complete genomic sequence of one earlier Chinese strain SC and one emergent strain HLJ8. Compared with other known sequences, we demonstrated that PRV strains from distinct geographical regions displayed divergent evolution. Additionally, we report for the first time, a recombination event between PRV strains, and show that strain SC is a recombinant of an endemic Chinese strain and a Bartha-vaccine-like strain. These results contribute to our understanding of PRV evolution.