The plasmid PE which harbored the whole hexon-encoding gene of egg drop syndrome virus(EDSV) was identified and the hexon protein gene was obtained from it by restriction endonucleases.The gene was then directionally inserted into the PphI/KpnI sites of pQE32 and fused with the 6×His gene.This recombinant plasmid was transformed into E.coli M15 for expression and induced with IPTG.It was demonstrated by SDS-PAGE and Western blot that one expressed protein,110kD in size,could be specifically recognized by polyclonal anti-EDSV serum.The objective product was principally soluble and accounted for 21% of the total cellular proteins.The protein was used to detect the existence of antiEDSV IgG in 41 clinical chicken sera by agar diffusion test,and the result was in accordance with that when EDSV was used as antigen.These results showed that the expressed hexon recombinant protein can be used as diagnostic antigen of EDSV.
