Cloning，Sequence Analysis and Expression in E ．coli of the EP0 Gene of Pseudorabies Virus Ea Strain

The 1 23 kb DNA fragment encoding the early protein EP0 of pseudombie8 virus(PRV)Ea strain was amplified by PCR technique and doned inm pBluescriptlI sk+．Thiee sequencing plasmids containing the partial fragment of the EPO gene were constructed and the sequences were obtained by ganger’S sequencing technique Cc~npared wi山PRV InFh strain．there were multipile site-muratiens and a deleted-mutation in the EP0 gene of PRV strain Ea，and the diversity-of anlino acid residu also existed，Then，the EP0 gene was in— serted into an expression vector，pET-28a，fused into the downstream of the 6xHis-Tag in fram e，to yidd the expression plasmid pETEP0 After induction by 球TG．a high expression of fusion protein was obtained． PAGE analysis and Western blotting showed that the fusion protein WaS 62kD an d the protein WaS specific toantisera against PRVEa strain si~dicated thatthe EP0 germ be expressedin l( )andthe ex— pression products have immtmo-genicity