Expression of S1 glycoprotein gene of infectious bronchitis virus (IBV) in Escherichia coli

The objective of this work is to provide S1 protein as a recombinant antigen in order to be used in diagnostic kits. Various strains of infectious bronchitis virus (IBV) were detected by the S1 glycoprotein gene. A prevalent strain 4/91 was frequently isolated in material from Iran. In this study we extracted RNA from vaccine strain 4/91 of IBV and amplified the S1 gene using RT-PCR and then cloned the S1 glycoprotein gene of infectious bronchitis virus into a cloning and expression vector. The result confirmed that a fragment of 900 bp in size was expressed and amplified. The results also showed that a protein about 33 KDa was expressed. Additionally, western blot assay confirmed the expression of S1 protein.   Key words: infectious bronchitis virus, S1 glycoprotein, cloning, E. coli.