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

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 ORFlb 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 &agnostic probe failed to amplify the correspondmg 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 ORFlb 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 whlch differential diagnostic probes can be applied.

Detection of Australian gill-associated virus (GAV) and lymphoid organ virus (LOV) of Penaeus monodon by RT-nested PCR

“…Recent molecular studies of YHV and GAV have shown that they are closely related but distinct viruses which are likely to be classified in the family Coron-aviridae (Cowley et al 1999). Wongteerasupaya et al (1995) demonstrated that YHV contains a singlestranded RNA genome.…”

Glycosylation of gp116 and gp64 envelope proteins of yellow head virus of Penaeus monodon shrimp

“…It is an enveloped, rod-shaped virus approximately 706180 nm in size (Chantanachookin et al, 1993;Flegel et al, 1995;Wongteerasupaya et al, 1995) and is classified as the type species of the genus Okavirus, family Roniviridae, in the order Nidovirales (Cowley et al, 1999;Walker et al, 2005;Ziebuhr et al, 2003). The YHV genome comprises a positive-sense, 26 662 nt ssRNA containing four ORFs designated ORF1a, ORF1b, ORF2 and ORF3 (Sittidilokratna et al, 2008;Wongteerasupaya et al, 1995).…”

Differences in the susceptibility of some penaeid prawn species to gill-associated virus (GAV) infection

“…It has been established previously that GAV from Australia and YHV from Thailand are distinct but closely related viruses (Spann et al 1997, Cowley et al 1999. P. monodon is a natural host of both GAV in Australia and YHV in Thailand.…”

“…GAV and YHV virions are rod-shaped, enveloped particles containing helical nucleocapsids that mature by budding at intracytoplasmic membranes , Spann et al 1997. Nucleotide sequence comparisons of the putative polymerase (ORF1b) genes have indicated that GAV and YHV are closely related but distinct viruses and are likely to be classified in the order Nidovirales, possibly in the family Coronaviridae (Cowley et al 1999(Cowley et al , 2000a.…”