DAO 36:153-157 (1999)  -  doi:10.3354/dao036153

Yellow head virus from Thailand and gill-associated virus from Australia are closely related but distinct prawn viruses

Jeff A. Cowley1,*, Christine M. Dimmock1, Chainarong Wongteerasupaya2, Vichai Boonsaeng3, Sakol Panyim3, Peter J. Walker1

1CRC for Aquaculture, CSIRO Tropical Agriculture, PMB 3, Indooroopilly 4068, Australia
2Department of Biochemistry, Faculty of Medicine, Srinakharinwirot University, Sukhumvit 23, Bangkok 10110, Thailand
3Department of Biochemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand

ABSTRACT: Corresponding genomic regions of isolates of yellow head virus (YHV) from Thailand and gill-associated virus (GAV) from Australia were compared by RT-PCR and sequence analysis. PCR primers designed from sequences in the GAV ORF1b polyprotein gene amplified the corresponding 577 nucleotide region of the YHV genome. Comparison of the amplified region indicated 85.1% nucleotide and 95.8% amino acid sequence identity. YHV PCR primers designed to amplify a 135 nucleotide product previously described as a YHV diagnostic probe failed to amplify the corresponding product from GAV RNA. However, the cognate GAV sequence for this and another recently reported YHV sequence were located in an upstream region of the ORF1b gene. A comparison of these sequences indicated identities of 83.0 and 80.9% at the nucleotide level and 86.7 and 86.5% at the amino acid level, respectively. The data indicate that GAV and YHV are closely related but distinct viruses for which differential diagnostic probes can be applied.


KEY WORDS: Yellow head virus (YHV) · Gill-associated virus (GAV) · Lymphoid organ virus (LOV) · Penaeus monodon · RT-PCR · Sequence analysis


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