| yellow head virus from thailand and gill-associated virus from australia are closely related but distinct prawn viruses. | 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 ... | 1999 | 10399042 |
| detection of australian gill-associated virus (gav) and lymphoid organ virus (lov) of penaeus monodon by rt-nested pcr. | a highly sensitive test based on reverse transcription followed by nested polymerase chain reaction (rt-npcr) was developed to detect the australian yellow-head-like viruses, gill-associated virus (gav) and lymphoid organ virus (lov) of penaeus monodon. the rt-npcr detected viral rna in as little as 10 fg lymphoid organ total rna isolated from gav-infected p. monodon. amplification of serial dilutions of a gav cdna clone showed that the nested pcr was sufficiently sensitive to detect a single ge ... | 2000 | 10768283 |
| gill-associated virus of penaeus monodon prawns: an invertebrate virus with orf1a and orf1b genes related to arteri- and coronaviruses. | a 20089 nucleotide (nt) sequence was determined for the 5' end of the (+)-ssrna genome of gill-associated virus (gav), a yellow head-like virus infecting penaeus monodon prawns. clones were generated from a approximately 22 kb dsrna purified from lymphoid organ total rna of gav-infected prawns. the region contains a single gene comprising two long overlapping open reading frames, orf1a and orf1b, of 4060 and 2646 amino acids, respectively. the orfs are structurally related to the orf1a and orf1a ... | 2000 | 10811931 |
| differences in the susceptibility of some penaeid prawn species to gill-associated virus (gav) infection. | four species of penaeid prawn cultured in australia (penaeus monodon, penaeus esculentus, marsupenaeus japonicus and fenneropenaeus merguiensis) were injected with a virulent preparation of gill-associated virus (gav). p. monodon (average weight = 8.9, 13.9 and 19.2 g), p. esculentus (average weight = 19.5 g), f. merguiensis (average weight = 10.5 g), and small (average weight = 5.8 g) m. japonicus displayed overt signs of disease and mortalities which reached 82 to 100% within 23 d post-injecti ... | 2000 | 11104074 |
| diseases of the eye of farmed shrimp penaeus monodon. | lesions were found in the eyes of cultured shrimp penaeus monodon that displayed non-specific signs of disease, including lethargy, dark pigmentation, brown gills, empty midgut, anorexia, white tail muscle, necrosis of uropods and fouled cuticle. eye lesions were associated with sexual development in moribund shrimp in at least 1 disease event. suppurative inflammation, granuloma and malacia were observed in histological examination of the eye and the causative agents of lesions appear to be vib ... | 2000 | 11206731 |
| gill-associated virus of penaeus monodon prawns. molecular evidence for the first invertebrate nidovirus. | | 2001 | 11774504 |
| gill-associated nidovirus of penaeus monodon prawns transcribes 3'-coterminal subgenomic mrnas that do not possess 5'-leader sequences. | sequence analysis of the approximately 20 kb 5'-terminal portion of the ssrna genome of gill-associated virus (gav) of penaeus monodon prawns has previously established that it contains an orf1a-1b replicase gene equivalent to those of the coronavirus and arterivirus members of the order nidovirales. sequence analysis of the remaining approximately 6.2 kb of the gav genome downstream of orf1a-1b to a 3'-poly(a) tail has identified two highly conserved intergenic sequences in which 29/32 nucleoti ... | 2002 | 11907343 |
| complete orf1b-gene sequence indicates yellow head virus is an invertebrate nidovirus. | we report the sequence of an 8503 nucleotide (nt) region of the genome of yellow head virus (yhv) encompassing the open reading frame (orf) 1b gene. comparison with the sequence of australian gill-associated virus (gav) indicated that the region, comprising approximately 30% of the yhv genome, commences 268 nt upstream of the putative orf1a termination codon and continues through orf1b to a site 30 nt downstream of the orf2 initiation codon. yhv orf1a and orf1b overlap by 37 nt. mfold analysis o ... | 2002 | 12180709 |
| vertical transmission of gill-associated virus (gav) in the black tiger prawn penaeus monodon. | chronic gill-associated virus (gav) infection is endemic in penaeus monodon broodstock captured from north-east queensland in australia and in farmed shrimp produced from these. we investigated the role of vertical transmission in perpetuating the high prevalence of these chronic gav infections. reverse transcription (rt)-nested pcr detected gav in spermatophores and mature ovarian tissue from broodstock and in fertilized eggs and nauplii spawned from wild-fertilized females. in laboratory-reare ... | 2002 | 12180710 |
| the complete genome sequence of gill-associated virus of penaeus monodon prawns indicates a gene organisation unique among nidoviruses. | we report here a 5596 nt sequence comprising the 3'-end of the (+) ssrna genome of gill-associated virus (gav), an invertebrate nidovirus of penaeus monodon prawns. the sequence extends from a subgenomic rna start site 35 nt upstream of the 4923 nt orf3 gene to a 3'-poly(a) tail of the 26235 nt genome of gav. the putative 1640 amino acid (aa) orf3 protein (mw = 182049 da, pi = 6.62) contains 15 potential n-linked glycosylation sites, 15 potential o-linked glycosylation sites and six highly hydro ... | 2002 | 12376758 |
| the 3c-like proteinase of an invertebrate nidovirus links coronavirus and potyvirus homologs. | gill-associated virus (gav), a positive-stranded rna virus of prawns, is the prototype of newly recognized taxa (genus okavirus, family roniviridae) within the order nidovirales: in this study, a putative gav cysteine proteinase (3c-like proteinase [3cl(pro)]), which is predicted to be the key enzyme involved in processing of the gav replicase polyprotein precursors, pp1a and pp1ab, was characterized. comparative sequence analysis indicated that, like its coronavirus homologs, 3cl(pro) has a thr ... | 2003 | 12502857 |
| identification and analysis of gp116 and gp64 structural glycoproteins of yellow head nidovirus of penaeus monodon shrimp. | yellow head virus (yhv) is a major agent of disease in farmed penaeid shrimp. yhv virions purified from infected shrimp contain three major structural proteins of molecular mass 116 kda (gp116), 64 kda (gp64) and 20 kda (p20). two different staining methods indicated that the gp116 and gp64 proteins are glycosylated. here we report the complete nucleotide sequence of orf3, which encodes a polypeptide of 1666 amino acids with a calculated molecular mass of 185 713 da (pi=6.68). hydropathy analysi ... | 2003 | 12655087 |
| fatal, virus-associated peripheral neuropathy and retinopathy in farmed penaeus monodon in eastern australia. i. pathology. | lesions are described in farmed penaeus monodon affected with a previously unreported, fatal disease, 'peripheral neuropathy and retinopathy' (pnr). outbreaks, associated with minor to heavy mortalities, occurred in 22 of 25 ponds on a farm in eastern australia during the mid to late 1998/99 growout period. moribund prawns, 5 to 26 g mean body weight, gathered at pond edges and were typically reddish in colour, lethargic, with mild to moderate epibiotic fouling and 1 or more partially amputated ... | 2003 | 12691189 |
| detection of gill-associated virus (gav) by in situ hybridization during acute and chronic infections of penaeus monodon and p. esculentus. | chronic and acute gill-associated virus (gav) infections were examined by in situ hybridization (ish) using a dna probe targeting a 779 nucleotide region of the orf1b-gene. chronic gav infections were observed in healthy penaeus monodon collected from farms and healthy p. esculentus surviving experimental infection. during chronic-phase infections in both species, gav was detected only in partitioned foci of cells with hypertrophied nuclei (spheroids) within the lymphoid organ. acute-phase infec ... | 2003 | 14524496 |
| detection and differentiation of yellow head complex viruses using monoclonal antibodies. | three monoclonal antibodies (mabs) raised against pathogenic yellow head virus (yhv) from thailand were tested against tissues of shrimp from thailand, australia, ecuador and india that were purported to be infected with yellow head complex viruses. mabs v-3-2b and y-18 were specific to gp116 and gp64 envelope proteins, respectively, while y-19 was specific to a 20 kda putative nucleoprotein p20. as a preliminary step, the site of reactivity of the 3 mabs in yhv was determined by immuno-electron ... | 2003 | 14960031 |
| multiplex rt-nested pcr differentiation of gill-associated virus (australia) from yellow head virus (thailand) of penaeus monodon. | a multiplex rt-nested pcr has been developed to detect and differentiate the closely related prawn viruses, gill-associated virus (gav) from australia and yellow head virus (yhv) from thailand. rt-pcr using primers to conserved sequences in the orf1b gene amplified a 794 bp region of either gav or yhv. nested pcr using a conserved sense primer and either a gav- or yhv-specific antisense primer to a divergent sequence differentially amplified a 277 bp region of the primary pcr amplicon. multiplex ... | 2004 | 15019259 |
| quantitative real-time rt-pcr demonstrates that handling stress can lead to rapid increases of gill-associated virus (gav) infection levels in penaeus monodon. | gill-associated virus (gav) of the black tiger prawn penaeus monodon has been implicated as a cause of periodic production losses in australia since 1996. we report here the development of a real-time quantitative rt-pcr (qrt-pcr) for gav. a dilution series of in vitro transcribed rna was used to determine the sensitivity limit of the qrt-pcr and as a standard for gav quantification. a linear relationship between cycle threshold (ct) values and input rna was obtained over a wide concentration ra ... | 2004 | 15264715 |
| the gene encoding the nucleocapsid protein of gill-associated nidovirus of penaeus monodon prawns is located upstream of the glycoprotein gene. | the orf2 gene of gill-associated virus (gav) of penaeus monodon prawns resides 93 nucleotides downstream of the orf1a-orf1b gene and encodes a 144-amino-acid hydrophilic polypeptide (15,998 da; pi, 9.75) containing 20 basic (14%) and 13 acidic (9%) residues and 19 prolines (13%). antiserum to a synthetic orf2 peptide or an escherichia coli-expressed glutathione s-transferase-orf2 fusion protein detected a 20-kda protein in infected lymphoid organ and gill tissues in western blots. the gav orf2 f ... | 2004 | 15280504 |
| rt-nested pcr detection of mourilyan virus in australian penaeus monodon and its tissue distribution in healthy and moribund prawns. | mourilyan virus (mov) is a newly identified virus of penaeus monodon prawns that is genetically related to the uukuniemi virus and other phleboviruses of the bunyaviridae. this paper describes an rt-nested pcr test that can reliably detect between 2 and 6 copies of a synthetic mov rna. total rna isolated from the lymphoid organ, gills and haemocytes of p. monodon with moderate infections gave comparable amplicon yields in the rt-pcr step of the test. however, in prawns with extremely low-level i ... | 2005 | 16231634 |
| white-spot syndrome virus (wssv) introduction into the gulf of mexico and texas freshwater systems through imported, frozen bait-shrimp. | we analysed 20 boxes of, frozen imported bait-shrimp (china: parapenaeopsis sp. and metapenaeopsis sp.) and 8 boxes of native, frozen bait-shrimp (gulf of mexico: litopenaeus setiferus and farfantepenaeus duorarum) by rt-pcr or pcr for taura syndrome virus (tsv), yellowhead virus/gill-associated virus (yhv/gav), white-spot syndrome virus (wssv) and infectious hypodermal and hematopoietic necrosis virus (ihhnv). all 28 boxes of shrimp were negative for tsv, yhv/gav and ihhnv; 2 boxes of imported ... | 2006 | 16956056 |
| sensitivity and specificity of current diagnostic tests for gill-associated virus in penaeus monodon. | this study reports the sensitivity, specificity, positive predictive value (ppv), negative predictive value (npv) and accuracy between a reverse transcriptase-nested polymerase chain reaction (rt-npcr) and an enzyme-linked immunosorbent assay (elisa) for the detection of gill-associated virus (gav) from a sample of 120 penaeus monodon. subsequently, the same comparisons were applied to the elisa and haemagglutination (ha) assays for detection of gav from a second 120 prawns. the optical density ... | 2006 | 17169111 |
| a convenient immunochromatographic test strip for rapid diagnosis of yellow head virus infection in shrimp. | a simple yellow head virus (yhv) "strip test" was developed using monoclonal antibody y19 (against the p20 structural protein) conjugated with colloidal gold as the detector antibody. rabbit anti-recombinant p20 (rp20) protein antibody was used as a capture antibody at the test line (t) and goat anti-mouse igg antibody (gam) was used as the capture antibody at the control line (c). the ready-to-use strip was housed in a plastic case for convenient application and stored in the desiccated plastic ... | 2007 | 17188759 |
| a key gene of the rna interference pathway in the black tiger shrimp, penaeus monodon: identification and functional characterisation of dicer-1. | rna interference (rnai) is an evolutionarily conserved mechanism by which double-stranded rna (dsrna) initiates post-transcriptional silencing of homologous genes. here we report the amplification and characterisation of a full length cdna from black tiger shrimp (penaeus monodon) that encodes the bidentate rnaase iii dicer, a key component of the rnai pathway. the full length of the shrimp dicer (pm dcr1) cdna is 7629bp in length, including a 5' untranslated region (utr) of 130bp, a 3' utr of 7 ... | 2008 | 18166489 |
| rna transcription analysis and completion of the genome sequence of yellow head nidovirus. | yellow head virus (yhv) is a pathogen of the black tiger shrimp (penaeus monodon) and, with gill-associated virus (gav), is one of two known invertebrate nidoviruses. we describe sequences of the large replicase gene (orf1a) and 5'- and 3'-terminal utrs, completing the 26,662 nt sequence of the yhv genome. orf1a (12,219 nt) encodes a approximately 462,662 da polypeptide containing a putative 3c-like protease and a putative papain-like protease with the canonical c/h catalytic dyad and alpha+beta ... | 2008 | 18582978 |
| consensus rt-nested pcr detection of yellow head complex genotypes in penaeid shrimp. | a consensus rt-nested (n)pcr is described that detects the six distinct genotypic variants in the yellow head virus (yhv) complex. the pcr primers targeted orf1b gene regions more highly conserved amongst the reference strains of yhv (genotype 1) and gill-associated virus (gav, genotype 2) and a set of 57 field isolates containing multiple representatives of each genotype. the test employed short pcr (359 bp) and npcr (147 bp) amplicons to minimise the effects of rna degradation. to ensure < or ... | 2008 | 18706929 |
| detection of shrimp infectious myonecrosis virus by reverse transcription loop-mediated isothermal amplification combined with a lateral flow dipstick. | infectious myonecrosis virus (imnv) has caused a slowly progressive disease with cumulative mortalities of up to 70% or more in cultured penaeus (litopenaeus) vannamei in northeast brazil and indonesia. rapid detection of viruses by loop-mediated isothermal amplification (lamp) of genomic material with high specificity and sensitivity can be applied for diagnosis, monitoring and control of diseases in shrimp aquaculture. using an imnv template, successful detection was achieved after a 60-min rt ... | 2009 | 19022295 |
| homologous genetic recombination in the yellow head complex of nidoviruses infecting penaeus monodon shrimp. | yellow head virus (yhv) is a highly virulent pathogen of penaeus monodon shrimp. it is one of six known genotypes in the yellow head complex of nidoviruses which also includes mildly pathogenic gill-associated virus (gav, genotype 2) and four other genotypes (genotypes 3-6) that have been detected only in healthy shrimp. in this study, comparative phylogenetic analyses conducted on replicase- (orf1b) and glycoprotein- (orf3) gene amplicons identified 10 putative natural recombinants amongst 28 v ... | 2009 | 19487006 |
| in situ stress testing to identify australian black tiger prawns (penaeus monodon) free of gill-associated virus and mourilyan virus. | to identify whether black tiger prawns (penaeus monodon) in the weipa region of the gulf of carpentaria, queensland, are free of gill-associated virus (gav) and mourilyan virus (mov), which are endemic in p. monodon along the east coast of queensland. | 2009 | 19489783 |
| gill-associated virus and its association with decreased production of penaeus monodon in australian prawn farms. | gill-associated virus (gav) was found to be associated with decreased prawn, penaeus monodon, production when prawns from three farms (n = 45 ponds, 1800 prawns) were monitored for gav over the production season using a graded rt-npcr. the grading system used was a visualization of either the outer or inner nested pcr products. prevalence and loading of gav were associated with disease severity. ponds with a higher initial prevalence and a larger increase in gav load over the production period s ... | 2010 | 21118269 |
| pathogenicity of gill-associated virus and mourilyan virus during mixed infections of black tiger shrimp (penaeus monodon). | gill-associated virus (gav) and mourilyan virus (mov) can occur at very high prevalence in healthy black tiger shrimp (penaeus monodon) in eastern australia, and both have been detected in moribund shrimp collected from mid-crop mortality syndrome (mcms) outbreaks. experimental evidence presented here indicates that gav, but not mov, is the cause of mcms. firstly, in healthy p. monodon used for experimental infections, pre-existing mov genetic loads were very high (mean >10(9) viral rna copies μ ... | 2011 | 21216987 |
| penaeus monodon is protected against gill-associated virus by muscle injection but not oral delivery of bacterially expressed dsrnas. | gill-associated virus (gav) is a nidovirus that commonly infects penaeus monodon (black tiger shrimp) in eastern australia, causing morbidity and mortalities in the acute stage of disease. here we explored the possibility of inhibiting gav replication and disease using double-stranded (ds)rnas expressed in bacteria and delivered either orally or by muscle injection. to enhance potential rna interference (rnai) responses, 5 long dsrnas were used that targeted open reading frame 1a/1b (orf1a/b) ge ... | 2011 | 21797032 |
| RNA-binding domain in the nucleocapsid protein of gill-associated nidovirus of penaeid shrimp. | Gill-associated virus (GAV) infects Penaeus monodon shrimp and is the type species okavirus in the Roniviridae, the only invertebrate nidoviruses known currently. Electrophoretic mobility shift assays (EMSAs) using His(6)-tagged full-length and truncated proteins were employed to examine the nucleic acid binding properties of the GAV nucleocapsid (N) protein in vitro. The EMSAs showed full-length N protein to bind to all synthetic single-stranded (ss)RNAs tested independent of their sequence. Th ... | 2011 | 21857914 |
| identification and characterization of a ribose 2'-o-methyltransferase encoded by the ronivirus branch of nidovirales. | the order nidovirales currently comprises four virus families: arteriviridae, coronaviridae (divided into the subfamilies coronavirinae and torovirinae), roniviridae, and the recently recognized mesoniviridae rna cap formation and methylation have been best studied for coronaviruses, with emphasis on the identification and characterization of two virus-encoded methyltransferases (mtases) involved in rna capping, a guanine-n7-mtase and a ribose-2'-o-mtase. although bioinformatics analyses suggest ... | 2016 | 27170751 |
| new yellow head virus genotype (yhv7) in giant tiger shrimp penaeus monodon indigenous to northern australia. | in 2012, giant tiger shrimp penaeus monodon originally sourced from joseph bonaparte gulf in northern australia were examined in an attempt to identify the cause of elevated mortalities among broodstock at a queensland hatchery. nucleic acid extracted from ethanol-fixed gills of 3 individual shrimp tested positive using the oie yhv protocol 2 rt-pcr designed to differentiate yellow head virus (yhv1) from gill-associated virus (gav, synonymous with yhv2) and the oie yhv protocol 3 rt-nested pcr d ... | 2015 | 26290511 |