Cloning and sequencing of envelope proteins (VP19, VP28) and nucleocapsid proteins (VP15, VP35) of a white spot syndrome virus isolate from Korean shrimp

Abstract

Since our first report in 1998, white spot syndrome virus (WSSV) has become wide-spread on the southern and western coasts of Korea. Almost all shrimp in ponds die within 3 to 4 d after the first dead shrimp are observed with gross lesions ranging from abnormal red body discoloration to white spots in the cuticle. From one isolate, we cloned and sequenced WSSV genomic DNA coding for VP19 and VP28 envelope proteins and VP15 and VP35 nucleocapsid proteins. Putative protein sequences were submitted to GenBank and assigned accession numbers AY316119 (VP19), AY324881 (VP28), AY374120 (VP15) and AY325896 (VP35). At the nucleotide level, VP19, VP28 and VP15 sequences were, respectively, 99, 100 and 100% identical to those of China, Indonesia, Japan and the United States and the VP35 sequence was 100% identical to that of a Taiwanese isolate. The deduced amino-acid sequences were 99 to 100% identical to those from other countries. In VP19, C and T in the foreign isolates were replaced by T and A in the Korean isolate at Positions 57 and 218 nt, respectively, downstream of A (+) of the VP19 start codon. The change at Position 218 nt resulted in valine in the foreign isolates being replaced by aspartate in the Korean isolate.