Protective efficacy of recombinant wsv477 protein against white spot syndrome virus infection in the tiger shrimp Penaeus monodon

White spot syndrome virus (WSSV) is a highly virulent shrimp pathogen reported in almost all the shrimp producing nations causing huge economic loss to the aquaculture industry. In the present study, we investigated the efficacy of a recombinant wsv477 protein against WSSV infection in the tiger shrimp Penaeus monodon by intramuscular and oral administration. The wsv477 is a protein encoded by the non-structural gene wsv477, having a key role in DNA replication and proliferation of guanosine triphosphate (GTP)-binding protein. Non-structural gene wsv477 was amplified from genomic DNA, cloned in PQE30 vector and expressed in Escherichia coli SG cells using isopropyl-1-1-thio-b-d-galactoside (IPTG) inducer. Expression of the recombinant wsv477 protein was confirmed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis and the purified protein was used for in vivo study. Shrimp immunised with recombinant protein by intramuscular and oral methods showed a cumulative mortality of 40 and 30% following challenge, respectively. Our findings showed that wsv477 recombinant protein had better protection against WSSV infection when administrated through intramuscular route compared with oral method. Results obtained from this study suggest that wsv477 protein could be used to elicit immune response in P. monodon and for protection against WSSV infection.