[Studies on in vitro expression for gI gene of Marek's disease in E. coli by pGEX vector].

Glycoprotein I Gene(gI) was amplified from genomic DNA of Marek's disease virus (MDV) 648 strain by polymerase chain reaction(PCR). PCR product was cloned into pGEX-6p-1 according to the right open reading frame(ORF). The expression of GST-gI fusion protein was studied in detail on many factors including temperature, timing and IPTG. The curve for OD600 and the growing time of the recombinant bacteria is also established., which is helpful to find the optimal inducing time. GST-gI fusion protein was identified by SDS-PAGE and Western-blotting., and the result shows that the best concentration of IPTG is 0.2-0.5 mmol/L and inducing time have great effects on expression while temperature has little. The fusion protein was injected into mouse five times to identify its antigenicity and the result is positive in indirect fluorescent assay IFA.