XIE Jin-wen;SHEN Zhi-qiang;WANG Jin-liang;REN Yan-ling;GUAN Yu;MIAO Li-zhong

Research Center for Veterinary Propolis Vaccines Engineering Technology of Shandong Province; Binzhou 256600

Porcine parvovirus;NSl gene;Cloning;Prokaryotic expression

[ Objective] The research aimed to provide the theoretical basis for establishing a rapid diagnosis method for porcine parvovirus ( PPV). [Method] One pair of primers were designed according to PPV genome sequences on GenBank website and the sequencesof prokaryotic expression vector pET30a ( + ) with multiple cloning sites. The whole sequence of NSl gene in PPV SD1 strain was amplified by using PCR technology and the positive re-combinant plasmid was analyzed by sequencing and homology comparison. The prokaryotic expression recombinant plasmid PET30a/NSl was constructed to make its induction expression in Escherichia coli. [ Result] The target fragment with the length of 2 208 bp was obtained from PCR amplification. The nu-cleotide homologies between the cloned NSl gene and the reported relevant PPV genes were from 97.3 % to 99.4 % , which indicated that NSl gene had high conservation. But it had a 12-basepair successive deletion near the hydroxyl end. The cloned PPV NSl gene was successfully expressed in prokaryotic cell, and its expression products existed mostly in inclusion bodies. [Conclusion] The results of SDS-PAGE detection showed that the molecular weight of PPV NSl protein was 86 KD.