Yellow-head virus: a rhabdovirus-like pathogen of penaeid shrimp

Yellow-head virus (YHV), a highly virulent virus of cultured penaeid shrimp, was originally isolated from the black tiger shrimp Penaeus monodon in Thailand. It was initially described as a baculovirus, but was recently reported to be an RNA-containing virus. The present study reaffirms the genome of highly purified YHV to be an unsegmented single-stranded RNA with negative polarity and of approximately 22 kb size. When analysed by SDS-PAGE, the purified virus yielded at least 4 viral structural proteins of 170, 135, 67 and 22 kDa. The 135 kDa protein was determined to be glycosylated. YHV, as with VSV, a rhabdovirus, was found to agglutinate chicken red blood cells. The highly flexible enveloped bacilliform YHV particles measured 50-60 x 190-200 nm. Since the virus had a number of properties in common with rhabdoviruses, particularly plant rhabdoviruses, it was provisionally classfied as a rhabdovirus.