Infectious bronchitis (IB) is one of the most important viral diseases of poultry that causes significant economic loses to chicken industry worldwide. Infectious Bronchitis Virus causes a contagious and acute respiratory disease. Some nephrotropic serotypes of IBV cause nephritis. IBV is responsible for decrease of egg production and laying abnormal eggs. IB has no treatment and the only way to protect the chicken flocks is vaccination against the virus. Immunity to IBV has most often been assessed using serological assays; like enzyme-linked immunosorbent assay (ELISA). IBV (genus Gama coronavirus, family Coronaviridae) contains a 27.6 kb single stranded positive sense RNA. The genome encodes three major structural proteins; the spike (S) glycoprotein, the integral membrane glycoprotein (M), and the 43 to 50 kDa nucleocapsid (N) phosphoprotein .
The aim of this study was to prepare recombinant nucleocapsid protein. For this purpose after RNA extraction the corresponding gene with a length of 1227 bp was amplified by RT-PCR. Then this gene cloned into expression plasmid (pMAL-C2X) and recombinant plasmid was transferred to strain Rosetta of E.coli. Expression of protein N was detected by SDS-PAGE. The results of this study show Nucleocapsid recombinant protein could be expression whit high concentration in bacterial system.