RESUMO
Emaravirus is a recently established viral genus that includes two approved virus species: European mountain ash ringspot-associated virus (EMARaV) and Fig mosaic virus (FMV). Other described but unclassified viruses appear to share biological characteristics similar to emaraviruses, including segmented, negative-single stranded RNA genomes with enveloped virions approximately 80-200nm in diameter. Sequence analysis of emaravirus genomes revealed the presence of conserved amino acid sequences in the RNA-dependent RNA polymerase gene (RdRp) denoted as pre-motif A, motifs A and C. Degenerate oligonucleotide primers were developed to these conserved sequences and were shown to amplify in reverse transcription-polymerase chain reaction assay (RT-PCR) DNA fragments of 276bp and 360bp in size. These primers efficiently detected emaraviruses with known sequences available in the database (FMV and EMARaV); they also detected viruses with limited sequence information such as Pigeonpea sterility mosaic virus (PPSMV) and Maize red stripe virus (MRSV). The degenerate primers designed on pre-motif A and motif A sequences successfully amplified the four species used as positive controls (276bp), whereas those of motifs A and C failed to detect only MRSV. The amino acid sequences obtained from PPSMV and MRSV shared the highest identity with those of two other tentative species of the Emaravirus genus, Rose rosette virus (RRV) (69%) and Redbud yellow ringspot virus (RYRV) (60%), respectively. The phylogenetic tree constructed with 92 amino acid-long portions of polypeptide putatively encoded by RNA1 of definitive and tentative emaravirus species clustered PPSMV and MRSV in two separate clades close to RRV and Raspberry leaf blotch virus (RLBV), respectively. The newly developed degenerate primers have proved their efficacy in amplifying new emaravirus-specific sequences; accordingly, they could be useful in identifying new emaravirus-like species in nature.
Assuntos
Primers do DNA/genética , Vírus de Plantas/genética , Vírus de RNA/genética , RNA Polimerase Dependente de RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Vírus não Classificados/genética , Sequência de Aminoácidos , Análise por Conglomerados , Ficus , Filogenia , Vírus de Plantas/enzimologia , Vírus de RNA/enzimologia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Vírus não Classificados/enzimologia , Zea maysRESUMO
Maedi virus contains a ribonucleic acid (RNA) which can be resolved into three major components, namely, 62S, 33S, and 13S, by sucrose gradient centrifugation. The presence of RNA- and deoxyribonucleic acid (DNA)-dependent DNA polymerase in virions of maedi virus was demonstrated. The enzyme product could be converted into acid-soluble form by pancreatic deoxyribonuclease, but was resistant to digestion by pancreatic ribonuclease and to hydrolysis by NaOH.
Assuntos
RNA Viral/análise , DNA Polimerase Dirigida por RNA/análise , Vírus não Classificados/análise , Animais , Centrifugação com Gradiente de Concentração , Plexo Corióideo , Técnicas de Cultura , DNA Viral/biossíntese , Hidrólise , Adenomatose Pulmonar Ovina/microbiologia , RNA Viral/isolamento & purificação , DNA Polimerase Dirigida por RNA/metabolismo , Ribonucleases , Ovinos , Hidróxido de Sódio , Timidina/metabolismo , Nucleotídeos de Timina/metabolismo , Trítio , Uridina/metabolismo , Vírus não Classificados/enzimologia , Vírus não Classificados/crescimento & desenvolvimento , Vírus não Classificados/metabolismoAssuntos
Desoxirribonucleases/análise , Vírus não Classificados/enzimologia , Animais , Linhagem Celular , Sistema Livre de Células , Centrifugação com Gradiente de Concentração , Colífagos , Cricetinae , DNA de Cadeia Simples/metabolismo , DNA Viral/isolamento & purificação , DNA Viral/metabolismo , Desoxirribonucleases/metabolismo , Hidrólise , Rim , Desnaturação de Ácido Nucleico , Timidina , Trítio , Cultura de VírusRESUMO
The physical and biochemical characteristics of progressive pneumonia virus were found to be remarkably similar to those of the ribonucleic acid (RNA) tumor viruses. Significant findings included the presence of a 60 to 70S RNA genome, RNA-dependent deoxyribonucleic acid polymerase activity, and common morphological properties. This information correlates with previously reported biological observations and supports the provisional inclusion of enveloped RNA-containing "slow viruses" within the RNA tumor virus group.
Assuntos
Vírus não Classificados , Animais , Linhagem Celular , Centrifugação com Gradiente de Concentração , Precipitação Química , DNA Nucleotidiltransferases/metabolismo , Desoxirribonucleases , Etanol , Hidrólise , Masculino , Microscopia Eletrônica , Fosfatos/metabolismo , Isótopos de Fósforo , Adenomatose Pulmonar Ovina , RNA Viral/isolamento & purificação , Ribonucleases , Ovinos , Coloração e Rotulagem , Sacarose , Testículo , Timidina/metabolismo , Trítio , Uridina/metabolismo , Cultura de Vírus , Vírus não Classificados/classificação , Vírus não Classificados/enzimologia , Vírus não Classificados/isolamento & purificação , Vírus não Classificados/metabolismoRESUMO
A ribonucleic acid (RNA)-dependent RNA polymerase has been demonstrated in Kern Canyon virus (KCV) particles. The RNA product of the KCV polymerase hybridizes to KCV viral RNA. The properties of this viral enzyme have been characterized and compared with those of vesicular stomatitis virus (VSV). RNA polymerases from both viruses require similar conditions of temperature, pH, and detergent and magnesium concentrations for maximal synthesis of RNA. The RNA polymerase contained in the virion of KCV was more dependent on the presence of a sulfhydryl agent than was the VSV enzyme. Under optimal conditions, the specific activity of the VSV polymerase is about twenty-five times as great as that of KCV.
