polymerase chain reaction assay for avian polyomavirus.a polymerase chain reaction assay was developed for detection of budgerigar fledgling disease virus (bfdv). the assay used a single set of primers complementary to sequences located in the putative coding region for the bfdv vp1 gene. the observed amplification product had the expected size of 550 bp and was confirmed to derive from bfdv dna by its restriction digestion pattern. this assay was specific for bfdv and highly sensitive, being able to detect as few as 20 copies of the virus. by using ...19911647403
cloning and characterization of budgerigar fledgling disease virus, an avian polyomavirus.the dna of a virus isolated from fledgling budgerigars, designated bfdv, was cloned and analyzed with regard to its relationship to the polyomavirus subgroup of the papovavirus family. under relaxed conditions, the dna of bfdv cross-hybridized with the dnas of members of the polyomavirus subgroup, such as the mouse polyomavirus, the monkey viruses simian virus 40, stump-tailed macaque virus, and lymphotropic papovavirus, and the human viruses jcv and bkv. under stringent conditions, however, no ...19863010557
host restriction in the productive cycle of avian polyomavirus budgerigar fledgling disease virus type 3 depends on a single amino acid change in the common region of structural proteins vp2/vp3.the three avian polyomaviruses budgerigar fledgling disease virus types 1 to 3 (bfdv-1 to -3) contain genomes of identical size, 4981 bp. with differences of up to only 15 bp between the three genomes, these viruses show distinct tropism for cultured cells of various avian species: infection of chicken embryo (ce) cells with bfdv-1 and -2 results in virus propagation, whereas bfdv-3 is not replicated; all three viruses replicate, with different efficiencies, in infected muscovy duck cells. trans ...19948077924
safety, immunogenicity, and efficacy of an inactivated avian polyomavirus determine safety, immunogenicity, and efficacy of an inactivated avian polyomavirus vaccine in nonbudgerigar psittacine birds that varied in age, species, and immunologic status.19989492926
avian polymavirus in wild birds: genome analysis of isolates from falconiformes and psittaciformes.avian polyomavirus (apv) infections have been reported to cause fatal disease in a wide range of psittacine species. here we demonstrate apv infections in buzzards (buteo buteo) and in a falcon (falco tinnunculus) found dead in germany, and in lovebirds (agapornis pullaria) with fatal disease, wild-caught in moçambique. apv infection in buzzards was determined by pcr amplification of parts of the viral genome followed by southern blot hybridisation. the genomes of the isolates obtained from the ...19989739329
recombinant expression and modification analysis of protein agno-1b encoded by avian polyomavirus bfdv.among two pairs of agnoproteins encoded in upstream positions in the late mrnas of avian polyomavirus bfdv, either agno-1a or its splice derivative agno-1b are required for viral propagation. out of the two proteins both of which consist of multiple electrophoretic subspecies, the smaller and less complex agno-1b has been cdna-cloned into an influenza-virus /rna-polymerase i expression system for production of higher amounts of this protein in infected chicken embryo fibroblasts. fractional modi ...200010948993
serological cross-reactions between four polyomaviruses of birds using virus-like particles expressed in yeast.polyomaviruses are aetiological agents of fatal acute diseases in various bird species. genomic analysis revealed that avian polyomavirus (apyv), crow polyomavirus (cpyv), finch polyomavirus (fpyv) and goose hemorrhagic polyomavirus (ghpyv) are closely related to each other, but nevertheless form separate viral species; however, their serological relationship was previously unknown. as only apyv can be grown efficiently in tissue culture, virus-like particles (vlps) were generated by expression ...201222933666
Prevalence and genetic characterization of avian polyomavirus and psittacine beak and feather disease virus isolated from budgerigars in Mainland China.Budgerigar fledgling disease (BFD) and psittacine beak and feather disease (PBFD) are caused by avian polyomavirus (APV) and psittacine beak and feather disease virus (PBFDV), respectively. These diseases frequently infect psittacine birds and result in similar clinical manifestations. In this study, we observed the prevalence of PBFDV infection and a dual infection of APV and PBFDV in a budgerigar (Melopsittacus undulatus) in Mainland China for the first time. One PBFDV isolate and two APV isol ...201122002652
molecular characterization of avian polyomavirus isolated from psittacine birds based on the whole genome sequence avian polyomaviruses (apvs) were isolated from seven psittacine birds of four species. their whole genome sequences were genetically analyzed. comparing with the sequence of bfdv1 strain, nucleotide substitutions in the sequences of seven apv isolates were found at 63 loci and a high level of conservation of amino acid sequence in each viral protein (vp1, vp2, vp3, vp4, and t/t antigen) was predicted. an a-to-t nucleotide substitution was observed in non-control region of all seven apv seq ...200919345024
avian polyomavirus mutants with deletions in the vp4-encoding region show deficiencies in capsid assembly and virus release, and have reduced infectivity in chicken.avian polyomavirus (apv) is the causative agent of an acute fatal disease in psittacine and some non-psittacine birds. in contrast to mammalian polyomaviruses, the apv genome encodes the additional capsid protein vp4 and its variant vp4delta, truncated by an internal deletion. both proteins induce apoptosis. mutation of their common initiation codon prevents virus replication. here, the generation of replication competent deletion mutants expressing either vp4 or vp4delta is reported. in contras ...200717325354
development of a blocking enzyme-linked immunosorbent assay for the detection of avian polyomavirus-specific antibodies.avian polyomavirus, described originally as budgerigar fledgling disease virus, has been associated with devastating contagious disease outbreaks in budgerigar aviaries. at present, this virus affects a wide range of psittacine and non-psittacine birds worldwide, and the serum neutralisation test is used for the serodiagnosis of avian polyomavirus infections. a blocking enzyme-linked immunosorbent assay was developed for the screening of large numbers of sera collected from various avian species ...200010996638
agnoprotein 1a and agnoprotein 1b of avian polyomavirus are apoptotic inducers.avian polyomavirus (apv) causes an acute fatal disease in a variety of avian species. dna laddering indicating apoptosis was demonstrated in apv-infected chicken embryo (ce) cells. dna laddering, however, was not observed in vero cells infected with mammalian polyomavirus simian virus 40. expression of apv agnoprotein 1a and agnoprotein 1b induced apoptosis in insect cells and ce cells. an apv full-length plasmid transfected in ce cells induced apoptosis, and infectious virus was produced. after ...200010769059
evidence for translation of vp3 of avian polyomavirus bfdv by leaky ribosomal scanning.due to several incomplete splicing reactions, budgerigar fledgling disease virus (bfdv) late mature mrnas are either bicistronic or polycistronic with an agnogene located upstream of viral protein (vp) genes. while the bicistronic mrnas code for the vast majority of vp1, the polycistronic mrnas contain the coding sequences of vp2, vp3, and vp1 (as the most distal cistron relative to vp2 and vp3). in this work, the translation initiation mechanism of vp3 was investigated in chicken embryo fibrobl ...200010752562
experimental inoculation of avian polyomavirus in chemically and virally immunosuppressed chickens.the purpose of this series of experiments was to determine the effect of various types of immunosuppressive treatments (cyclophosphamide, infectious bursal disease virus [ibdv], chicken anemia virus [cav], and combination infection with ibdv and cav) on susceptibility of chickens to challenge with avian polyomavirus. in the first experiment, chickens were chemically bursectomized with intraperitoneal injections of cyclophosphamide; in the second study, chickens were orally inoculated with ibdv; ...199910494416
genetic diversity in twenty variants of the avian determine if different pathotypes of the avian polyomavirus (apv) exist and to compare the genomes of apvs originating from different geographic areas, dates, and species of birds, the partial sequences of 18 apvs were determined. new viral sequences were compared with three published apv sequences. two of the new viruses had identical sequences. forty point mutations were found at 31 loci. a 27-bp deletion was found in the vp2 and vp3 open reading frames of one virus. a duplication of the pu ...199910396633
development of a chicken model for studying avian polyomavirus infection.the purpose of this study was to develop a chicken model for studying the pathogenesis of avian polyomaviral infection. ninety-two 1-day-old specific-pathogen-free (spf) chicks were divided into the following three treatment groups: nontreated controls, treated with cyclosporine and treated with cyclophosphamide (cy). all birds were inoculated with polyomavirus; half were orally inoculated and half were inoculated by intraperitoneal (ip) injection. spontaneous mortality and lesion development co ...19968790889
failure of maternally derived yolk igg to reach detectable concentrations in the sera of nestling budgerigars (melopsittacus undulatus).transfer of maternal immunoglobulin g (igg) to the yolk and nestling was investigated in the budgerigar. specific antibodies to avian polyomavirus and newcastle disease virus could be detected in 82% of yolk extracts of eggs from seropositive hens. using a double immunodiffusion assay with anti-chicken igg antibodies, igg could also be detected in yolk supernatants with virus neutralizing activity. in all assays, igg concentrations in the yolk extracts were significantly less than those of the a ...19958719202
early and late pre-mrna processing of budgerigar fledgling disease virus 1: identification of viral rna 5' and 3' ends and internal splice junctions.budgerigar fledgling disease virus 1 (bfdv-1) is the first avian polyomavirus to be identified, and it possesses uncommon structural and biological properties. here we present an analysis of the processed viral rnas in infected chicken embryo fibroblast cells. two early and 18 late bfdv-1 mrnas were defined according to their 5' ends and internal splice patterns. in the early region of the genome an incomplete splice reaction covering 195 nt is responsible for creating two mrnas that could encod ...19957844527
nuclear localization of avian polyomavirus structural protein vp1 is a prerequisite for the formation of virus-like particles.virions of polyomaviruses consist of the major structural protein vp1, the minor structural proteins vp2 and vp3, and the viral genome associated with histones. an additional structural protein, vp4, is present in avian polyomavirus (apv) particles. as it had been reported that expression of apv vp1 in insect cells did not result in the formation of virus-like particles (vlp), the prerequisites for particle formation were analyzed. to this end, recombinant influenza viruses were created to (co)e ...200414694124
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