CA gene prokaryotic expression and the antiserum preparation of Jaagsiekte sheep retrovirus

To express the capsid antigen(CA) gene of Jaagsiekte sheep retrovirus(JSRV) and prepare the antiserum against the virus,the CA gene was amplified by PCR from JSRV proviral DNA with a pair of primers designed according to the CA gene of JSRV in GenBank.Subsequently,the CA gene was cloned into pET-28a(+) for expression in E.coli and the recombinant CA protein was about 28 ku,mainly in soluble form,detected by SDS-PAGE.In addition,the antiserum was prepared from rabbits immunized with the purified recombinant protein.Western blot showed that the antiserum was able to recognize both of the recombinant CA pretein and the native virus protein,which provided the basis for the establishment of the ELISA method to detect the JSRV infection in sheep.