DEVELOPMENT OF A POLYMERASE CHAIN-REACTION (PCR) PROCEDURE FOR THE DETECTION OF BACULOVIRUS ASSOCIATED WITH WHITE SPOT SYNDROME (WSBV) IN PENAEID SHRIMP

The causative viral agent was purified from diseased shrimp Penaeus ja ponicus with white spot syndrome (WSBV). Several hundred clones were o btained from libraries of the purified viral genomic DNA. According to the results of nucleotide sequence analysis, none of the WSBV clones showed considerable sequence homology with those of other known viruse s, indicating that WSBV is a new virus causing a serious disease in sh rimp. Based on the sequence data of WSBV genomic DNA, a pair of polyme rase chain reaction (PCR) primers was designed. After 30 cycles of PCR amplification of viral genomic DNA extracted from WSBV, a single prod uct of the expected size was detected. Southern blot hybridization con firmed that the amplified product was specific to the DNA of WSBV. The PCR system was able to detect 1 pg of WSBV DNA after 30 cycles, and e fficiently amplify the target region of WSBV gene in the total nucleic acids extracted either from the diseased shrimp or hatchery shrimp wi th no signs of viral infection.