[Cloning and expression of the envelope glycoprotein gD gene of pseudorabies virus EA strain]

The envelope glycoprotein gD gene of pseudorabies virus Ea strain was cloned via PCR technique. Sequence analysis displayed 98% nucleotide sequence homology and 97% deduced amino acid sequence homology between our cloned gD gene and PRV Rice strain gD gene. The recombinant transfer plasmid pSX35A-gD was obtained by inserting D gene into the baculovirus transfer vector pSX35A with whole-phase promoter cassette, then transfected insect cell Hi5 with linearized AcMNPV-OCC- virus DNA, and formed recombinant baculoviruses AcMNPV-OCC(+)-gD by homologous recombination in insect cell. Recombinant baculoviruses infected insect cell Hi5 after being purified by plaque assay. Both SDS-PAGE and Western-blotting showed glycoprotein gD with a molecular weight of about 47 kD was expressed specifically, product was about 6.2% of total cellular protein, and expressed gD was of immunogenicity.