Ja. Cowley et al., Yellow head virus from Thailand and gill-associated virus from Australia are closely related but distinct prawn viruses, DIS AQU ORG, 36(2), 1999, pp. 153-157
Corresponding genomic regions of isolates of yellow head virus (YHV) from T
hailand and gill-associated virus (GAV) from Australia were compared by RT-
PCR and sequence analysis. PCR primers designed from sequences in the GAV O
RF1b polyprotein gene amplified the corresponding 577 nucleotide region of
the YHV genome. Comparison of the amplified region indicated 85.1% nucleoti
de and 95.8% amino acid sequence identity. YHV PCR primers designed to ampl
ify a 135 nucleotide product previously described as a YHV diagnostic probe
failed to amplify the corresponding product from GAV RNA. However, the cog
nate GAV sequence for this and another recently reported YHV sequence were
located in an upstream region of the ORF1b gene. A comparison of these sequ
ences indicated identities of 83.0 and 80.9 % at the nucleotide level and 8
6.7 and 86.5 % at the amino acid level, respectively. The data indicate tha
t GAV and YHV are closely related but distinct viruses for which differenti
al diagnostic probes can be applied.