Defective interfering (DI) RNAs, helper virus-dependent deletion mutant RNAs derived from the parental viral genomic RNA during replication, have been described for most RNA virus taxonomic groups. We now report that DI RNA production in the chestnut blight fungus, Cryphonectria parasitica, persistently infected by virulence-attenuating positive sense RNA hypoviruses, depends on one of two host...

Fragaria chiloensis latent virus (FClLV), a member of the genus Ilarvirus was first identified in the early 1990s. Double-stranded RNA was extracted from FClLV infected plants and cloned. The complete nucleotide sequence of the virus has been elucidated. RNA 1 encodes a protein with methyltransferase and helicase enzymatic motifs while RNA 2 encodes the viral RNA dependent RNA polymerase and an...

Two lines of evidence support the view that the replication of ribonucleic acid-containing animal viruses proceeds via RNAdirected synthesis of RNA. It has been shown that RNA viruses continue to replicate under conditions in which synthesis of deoxyribonucleic acid and the DNB-dependent synthesis of RNA are artificially suppressed (l-3). Furthermore, in certain mammalian cell lines there is ev...

Viruses with segmented RNA genomes must package the correct number of segments for synthesis of infectious virus particles. Recent studies suggest that the members of the Reoviridae family with segmented double-stranded RNA genomes achieve this challenging task by forming RNA networks of segments prior to their recruitment into the assembling capsid albeit direct evidence is still lacking. Here...

Avian myeloblasts infected with BAI strain A avian tumor virus were cultured in vitro and treated with actinomycin D. The effects of the drug on cell growth and death and the synthe sis of cell and virus RNA were examined. Actinomycin D (AD) concentrations of 0.01-0.05 tig/ml caused cell damage and death at proportional rates, and, as shown in earlier work, inhibited cell RNA synthesis up to 60...

abstract potato virus a (pva) is one of the members of genus potyvirus. pva particles are straight to slightly flexuous rods and contain of single stranded rna. in the spring and summer of 2005, sampling accomplished to determine potato virus a from potato fields in northern and razavi khorasan provinces. samples with mosaic, shining and rolling of leaves carried in ice chamber to laboratory fo...

The genome of severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) has an untranslated region (UTR) that enhances the replication and transcription RNA, subgenomic RNA (sgRNA) which encodes 4 structural proteins are essential for viral replication. host cell SARS CoV-2 expresses important enzyme called TMPRSS2 protease allows virus to invade cell. Peptide conjugated phosphorodiamidate m...

We developed a system for complete replication of encephalomyocarditis virus (EMCV) in a test tube by using an in vitro translation extract from Krebs-2 cells. Efficient virus synthesis occurred in a narrow range of Mg(2+) and EMCV RNA concentrations. Excess input RNA impaired RNA replication and virus production but not translation. This suggests the existence of a negative-feedback mechanism ...

The search for successful therapies of infections with the coronavirus SARS-CoV-2 is ongoing. We tested inhibition host cell nucleotide synthesis as a promising strategy to decrease replication SARS-CoV-2-RNA, thus diminishing formation virus progeny. Methotrexate (MTX) an established drug cancer therapy and induce immunosuppression. inhibits dihydrofolate reductase other enzymes required nucle...

While dengue virus is thought to replicate in mononuclear phagocytic cells in vivo, attempts to detect it in peripheral blood mononuclear cells (PBMC) by virus isolation or antigen detection have had variable and generally low rates. In this study, we developed a reverse transcription (RT)-real-time PCR assay to quantify positive- and negative-sense RNA of dengue virus type 2 within the cells. ...