Viruses whose genetic material is RNA.
Ribonucleic acid that makes up the genetic material of viruses.
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.
Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.
The type species of ORTHOPOXVIRUS, related to COWPOX VIRUS, but whose true origin is unknown. It has been used as a live vaccine against SMALLPOX. It is also used as a vector for inserting foreign DNA into animals. Rabbitpox virus is a subspecies of VACCINIA VIRUS.
Viruses parasitic on plants higher than bacteria.
A process that changes the nucleotide sequence of mRNA from that of the DNA template encoding it. Some major classes of RNA editing are as follows: 1, the conversion of cytosine to uracil in mRNA; 2, the addition of variable number of guanines at pre-determined sites; and 3, the addition and deletion of uracils, templated by guide-RNAs (RNA, GUIDE).
Viruses whose nucleic acid is DNA.
The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.
RNA consisting of two strands as opposed to the more prevalent single-stranded RNA. Most of the double-stranded segments are formed from transcription of DNA by intramolecular base-pairing of inverted complementary sequences separated by a single-stranded loop. Some double-stranded segments of RNA are normal in all organisms.
Process of growing viruses in live animals, plants, or cultured cells.
Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.
The assembly of VIRAL STRUCTURAL PROTEINS and nucleic acid (VIRAL DNA or VIRAL RNA) to form a VIRUS PARTICLE.
A general term for diseases produced by viruses.
The type species of ALPHAVIRUS normally transmitted to birds by CULEX mosquitoes in Egypt, South Africa, India, Malaya, the Philippines, and Australia. It may be associated with fever in humans. Serotypes (differing by less than 17% in nucleotide sequence) include Babanki, Kyzylagach, and Ockelbo viruses.
Viruses which lack a complete genome so that they cannot completely replicate or cannot form a protein coat. Some are host-dependent defectives, meaning they can replicate only in cell systems which provide the particular genetic function which they lack. Others, called SATELLITE VIRUSES, are able to replicate only when their genetic defect is complemented by a helper virus.
The expelling of virus particles from the body. Important routes include the respiratory tract, genital tract, and intestinal tract. Virus shedding is an important means of vertical transmission (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A species of POLYOMAVIRUS originally isolated from Rhesus monkey kidney tissue. It produces malignancy in human and newborn hamster kidney cell cultures.
Proteins found in any species of virus.
Enzymes that catalyze DNA template-directed extension of the 3'-end of an RNA strand one nucleotide at a time. They can initiate a chain de novo. In eukaryotes, three forms of the enzyme have been distinguished on the basis of sensitivity to alpha-amanitin, and the type of RNA synthesized. (From Enzyme Nomenclature, 1992).
The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
The type species of MORBILLIVIRUS and the cause of the highly infectious human disease MEASLES, which affects mostly children.
The type species of LYSSAVIRUS causing rabies in humans and other animals. Transmission is mostly by animal bites through saliva. The virus is neurotropic multiplying in neurons and myotubes of vertebrates.
Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.
A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.
A subtype of INFLUENZA A VIRUS with the surface proteins hemagglutinin 1 and neuraminidase 1. The H1N1 subtype was responsible for the Spanish flu pandemic of 1918.
The complete genetic complement contained in a DNA or RNA molecule in a virus.
The type species of VESICULOVIRUS causing a disease symptomatically similar to FOOT-AND-MOUTH DISEASE in cattle, horses, and pigs. It may be transmitted to other species including humans, where it causes influenza-like symptoms.
The functional hereditary units of VIRUSES.
Established cell cultures that have the potential to propagate indefinitely.
A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE). It can infect birds and mammals. In humans, it is seen most frequently in Africa, Asia, and Europe presenting as a silent infection or undifferentiated fever (WEST NILE FEVER). The virus appeared in North America for the first time in 1999. It is transmitted mainly by CULEX spp mosquitoes which feed primarily on birds, but it can also be carried by the Asian Tiger mosquito, AEDES albopictus, which feeds mainly on mammals.
An enzyme that catalyses RNA-template-directed extension of the 3'- end of an RNA strand by one nucleotide at a time, and can initiate a chain de novo. (Enzyme Nomenclature, 1992, p293)
A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 5 and neuraminidase 1. The H5N1 subtype, frequently referred to as the bird flu virus, is endemic in wild birds and very contagious among both domestic (POULTRY) and wild birds. It does not usually infect humans, but some cases have been reported.
A family of proteins that promote unwinding of RNA during splicing and translation.
The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.
A group of viruses in the PNEUMOVIRUS genus causing respiratory infections in various mammals. Humans and cattle are most affected but infections in goats and sheep have also been reported.
The relationships of groups of organisms as reflected by their genetic makeup.
A CELL LINE derived from the kidney of the African green (vervet) monkey, (CERCOPITHECUS AETHIOPS) used primarily in virus replication studies and plaque assays.
The infective system of a virus, composed of the viral genome, a protein core, and a protein coat called a capsid, which may be naked or enclosed in a lipoprotein envelope called the peplos.
The type species of the genus ORTHOHEPADNAVIRUS which causes human HEPATITIS B and is also apparently a causal agent in human HEPATOCELLULAR CARCINOMA. The Dane particle is an intact hepatitis virion, named after its discoverer. Non-infectious spherical and tubular particles are also seen in the serum.
A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.
A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 3 and neuraminidase 2. The H3N2 subtype was responsible for the Hong Kong flu pandemic of 1968.
Viruses which produce a mottled appearance of the leaves of plants.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The outer protein protective shell of a virus, which protects the viral nucleic acid.
Substances elaborated by viruses that have antigenic activity.
Any of the processes by which cytoplasmic factors influence the differential control of gene action in viruses.
Viruses that produce tumors.
Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.
RNA that has catalytic activity. The catalytic RNA sequence folds to form a complex surface that can function as an enzyme in reactions with itself and other molecules. It may function even in the absence of protein. There are numerous examples of RNA species that are acted upon by catalytic RNA, however the scope of this enzyme class is not limited to a particular type of substrate.
Deoxyribonucleic acid that makes up the genetic material of viruses.
The mechanism by which latent viruses, such as genetically transmitted tumor viruses (PROVIRUSES) or PROPHAGES of lysogenic bacteria, are induced to replicate and then released as infectious viruses. It may be effected by various endogenous and exogenous stimuli, including B-cell LIPOPOLYSACCHARIDES, glucocorticoid hormones, halogenated pyrimidines, IONIZING RADIATION, ultraviolet light, and superinfecting viruses.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
The ability of a pathogenic virus to lie dormant within a cell (latent infection). In eukaryotes, subsequent activation and viral replication is thought to be caused by extracellular stimulation of cellular transcription factors. Latency in bacteriophage is maintained by the expression of virally encoded repressors.
A large family of RNA helicases that share a common protein motif with the single letter amino acid sequence D-E-A-D (Asp-Glu-Ala-Asp). In addition to RNA helicase activity, members of the DEAD-box family participate in other aspects of RNA metabolism and regulation of RNA function.
Method for measuring viral infectivity and multiplication in CULTURED CELLS. Clear lysed areas or plaques develop as the VIRAL PARTICLES are released from the infected cells during incubation. With some VIRUSES, the cells are killed by a cytopathic effect; with others, the infected cells are not killed but can be detected by their hemadsorptive ability. Sometimes the plaque cells contain VIRAL ANTIGENS which can be measured by IMMUNOFLUORESCENCE.
A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. It functions in the nucleoplasmic structure and transcribes DNA into RNA. It has different requirements for cations and salt than RNA polymerase I and is strongly inhibited by alpha-amanitin. EC
Membrane glycoproteins from influenza viruses which are involved in hemagglutination, virus attachment, and envelope fusion. Fourteen distinct subtypes of HA glycoproteins and nine of NA glycoproteins have been identified from INFLUENZA A VIRUS; no subtypes have been identified for Influenza B or Influenza C viruses.
Nucleic acid structures found on the 5' end of eukaryotic cellular and viral messenger RNA and some heterogeneous nuclear RNAs. These structures, which are positively charged, protect the above specified RNAs at their termini against attack by phosphatases and other nucleases and promote mRNA function at the level of initiation of translation. Analogs of the RNA caps (RNA CAP ANALOGS), which lack the positive charge, inhibit the initiation of protein synthesis.
The processes of RNA tertiary structure formation.
A species of ALPHAVIRUS isolated in central, eastern, and southern Africa.
The type species of RESPIROVIRUS in the subfamily PARAMYXOVIRINAE. It is the murine version of HUMAN PARAINFLUENZA VIRUS 1, distinguished by host range.
Viruses whose taxonomic relationships have not been established.
A family of RNA viruses causing INFLUENZA and other diseases. There are five recognized genera: INFLUENZAVIRUS A; INFLUENZAVIRUS B; INFLUENZAVIRUS C; ISAVIRUS; and THOGOTOVIRUS.
A species of RESPIROVIRUS also called hemadsorption virus 2 (HA2), which causes laryngotracheitis in humans, especially children.
The type species of RUBULAVIRUS that causes an acute infectious disease in humans, affecting mainly children. Transmission occurs by droplet infection.
Proteins that form the CAPSID of VIRUSES.
The interactions between a host and a pathogen, usually resulting in disease.
A sequence of successive nucleotide triplets that are read as CODONS specifying AMINO ACIDS and begin with an INITIATOR CODON and end with a stop codon (CODON, TERMINATOR).
The extent to which an RNA molecule retains its structural integrity and resists degradation by RNASE, and base-catalyzed HYDROLYSIS, under changing in vivo or in vitro conditions.
A genus of FLAVIVIRIDAE causing parenterally-transmitted HEPATITIS C which is associated with transfusions and drug abuse. Hepatitis C virus is the type species.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Species of the genus LENTIVIRUS, subgenus primate immunodeficiency viruses (IMMUNODEFICIENCY VIRUSES, PRIMATE), that induces acquired immunodeficiency syndrome in monkeys and apes (SAIDS). The genetic organization of SIV is virtually identical to HIV.
The type species of TOBAMOVIRUS which causes mosaic disease of tobacco. Transmission occurs by mechanical inoculation.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.
A multistage process that includes cloning, physical mapping, subcloning, sequencing, and information analysis of an RNA SEQUENCE.
A genus of plant viruses that infects ANGIOSPERMS. Transmission occurs mechanically and through soil, with one species transmitted via a fungal vector. The type species is Tomato bushy stunt virus.
Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.
Ribonucleic acid in fungi having regulatory and catalytic roles as well as involvement in protein synthesis.
RNA molecules which hybridize to complementary sequences in either RNA or DNA altering the function of the latter. Endogenous antisense RNAs function as regulators of gene expression by a variety of mechanisms. Synthetic antisense RNAs are used to effect the functioning of specific genes for investigative or therapeutic purposes.
Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.
A genus of tripartite plant viruses in the family BROMOVIRIDAE. Transmission is by beetles. Brome mosaic virus is the type species.
Group of alpharetroviruses (ALPHARETROVIRUS) producing sarcomata and other tumors in chickens and other fowl and also in pigeons, ducks, and RATS.
Viral proteins that are components of the mature assembled VIRUS PARTICLES. They may include nucleocapsid core proteins (gag proteins), enzymes packaged within the virus particle (pol proteins), and membrane components (env proteins). These do not include the proteins encoded in the VIRAL GENOME that are produced in infected cells but which are not packaged in the mature virus particle,i.e. the so called non-structural proteins (VIRAL NONSTRUCTURAL PROTEINS).
A species in the genus HEPATOVIRUS containing one serotype and two strains: HUMAN HEPATITIS A VIRUS and Simian hepatitis A virus causing hepatitis in humans (HEPATITIS A) and primates, respectively.
The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.
The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).
A family of RNA viruses that infect fungi and protozoa. There are three genera: TOTIVIRUS; GIARDIAVIRUS; and LEISHMANIAVIRUS.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
A plant genus of the family SOLANACEAE. Members contain NICOTINE and other biologically active chemicals; its dried leaves are used for SMOKING.
Insertion of viral DNA into host-cell DNA. This includes integration of phage DNA into bacterial DNA; (LYSOGENY); to form a PROPHAGE or integration of retroviral DNA into cellular DNA to form a PROVIRUS.
DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.
A family of RNA viruses infecting insects and fish. There are two genera: Alphanodavirus and Betanodavirus.
The type species of ALPHARETROVIRUS producing latent or manifest lymphoid leukosis in fowl.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
The type species of APHTHOVIRUS, causing FOOT-AND-MOUTH DISEASE in cloven-hoofed animals. Several different serotypes exist.
The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.
The binding of virus particles to receptors on the host cell surface. For enveloped viruses, the virion ligand is usually a surface glycoprotein as is the cellular receptor. For non-enveloped viruses, the virus CAPSID serves as the ligand.
A species of POLYOMAVIRUS apparently infecting over 90% of children but not clearly associated with any clinical illness in childhood. The virus remains latent in the body throughout life and can be reactivated under certain circumstances.
Infections produced by oncogenic viruses. The infections caused by DNA viruses are less numerous but more diverse than those caused by the RNA oncogenic viruses.
Visible morphologic changes in cells infected with viruses. It includes shutdown of cellular RNA and protein synthesis, cell fusion, release of lysosomal enzymes, changes in cell membrane permeability, diffuse changes in intracellular structures, presence of viral inclusion bodies, and chromosomal aberrations. It excludes malignant transformation, which is CELL TRANSFORMATION, VIRAL. Viral cytopathogenic effects provide a valuable method for identifying and classifying the infecting viruses.
A genus of the family RHABDOVIRIDAE that infects a wide range of vertebrates and invertebrates. The type species is VESICULAR STOMATITIS INDIANA VIRUS.
A species of POLYOMAVIRUS, originally isolated from the brain of a patient with progressive multifocal leukoencephalopathy. The patient's initials J.C. gave the virus its name. Infection is not accompanied by any apparent illness but serious demyelinating disease can appear later, probably following reactivation of latent virus.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Virus diseases caused by the ORTHOMYXOVIRIDAE.
The type species of PNEUMOVIRUS and an important cause of lower respiratory disease in infants and young children. It frequently presents with bronchitis and bronchopneumonia and is further characterized by fever, cough, dyspnea, wheezing, and pallor.
The type species of ORBIVIRUS causing a serious disease in sheep, especially lambs. It may also infect wild ruminants and other domestic animals.
A strain of Murine leukemia virus (LEUKEMIA VIRUS, MURINE) arising during the propagation of S37 mouse sarcoma, and causing lymphoid leukemia in mice. It also infects rats and newborn hamsters. It is apparently transmitted to embryos in utero and to newborns through mother's milk.
RNA transcripts of the DNA that are in some unfinished stage of post-transcriptional processing (RNA PROCESSING, POST-TRANSCRIPTIONAL) required for function. RNA precursors may undergo several steps of RNA SPLICING during which the phosphodiester bonds at exon-intron boundaries are cleaved and the introns are excised. Consequently a new bond is formed between the ends of the exons. Resulting mature RNAs can then be used; for example, mature mRNA (RNA, MESSENGER) is used as a template for protein production.
Biological properties, processes, and activities of VIRUSES.
Short chains of RNA (100-300 nucleotides long) that are abundant in the nucleus and usually complexed with proteins in snRNPs (RIBONUCLEOPROTEINS, SMALL NUCLEAR). Many function in the processing of messenger RNA precursors. Others, the snoRNAs (RNA, SMALL NUCLEOLAR), are involved with the processing of ribosomal RNA precursors.
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
A species of RESPIROVIRUS frequently isolated from small children with pharyngitis, bronchitis, and pneumonia.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
RNA which does not code for protein but has some enzymatic, structural or regulatory function. Although ribosomal RNA (RNA, RIBOSOMAL) and transfer RNA (RNA, TRANSFER) are also untranslated RNAs they are not included in this scope.
A genus of the family HERPESVIRIDAE, subfamily ALPHAHERPESVIRINAE, consisting of herpes simplex-like viruses. The type species is HERPESVIRUS 1, HUMAN.
Pneumovirus infections caused by the RESPIRATORY SYNCYTIAL VIRUSES. Humans and cattle are most affected but infections in goats and sheep have been reported.
A species in the ORTHOBUNYAVIRUS genus of the family BUNYAVIRIDAE. A large number of serotypes or strains exist in many parts of the world. They are transmitted by mosquitoes and infect humans in some areas.
A species of ARTERIVIRUS causing reproductive and respiratory disease in pigs. The European strain is called Lelystad virus. Airborne transmission is common.
A group of viruses in the genus PESTIVIRUS, causing diarrhea, fever, oral ulcerations, hemorrhagic syndrome, and various necrotic lesions among cattle and other domestic animals. The two species (genotypes), BVDV-1 and BVDV-2 , exhibit antigenic and pathological differences. The historical designation, BVDV, consisted of both (then unrecognized) genotypes.
Ribonucleic acid in plants having regulatory and catalytic roles as well as involvement in protein synthesis.
The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.
A positive-stranded RNA virus species in the genus HEPEVIRUS, causing enterically-transmitted non-A, non-B hepatitis (HEPATITIS E).
The study of the structure, growth, function, genetics, and reproduction of viruses, and VIRUS DISEASES.
The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.
The type species of the genus ARTERIVIRUS and the etiologic agent of an important equine respiratory disease causing abortion, pneumonia, or other infections.
Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)
The type species of the FLAVIVIRUS genus. Principal vector transmission to humans is by AEDES spp. mosquitoes.
Virulent bacteriophage and sole member of the genus Cystovirus that infects Pseudomonas species. The virion has a segmented genome consisting of three pieces of doubled-stranded DNA and also a unique lipid-containing envelope.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Diseases of plants.
Proteins that bind to RNA molecules. Included here are RIBONUCLEOPROTEINS and other proteins whose function is to bind specifically to RNA.
A species of GAMMARETROVIRUS causing leukemia, lymphosarcoma, immune deficiency, or other degenerative diseases in cats. Several cellular oncogenes confer on FeLV the ability to induce sarcomas (see also SARCOMA VIRUSES, FELINE).
Inactivation of viruses by non-immune related techniques. They include extremes of pH, HEAT treatment, ultraviolet radiation, IONIZING RADIATION; DESICCATION; ANTISEPTICS; DISINFECTANTS; organic solvents, and DETERGENTS.
Family of RNA viruses that infects birds and mammals and encodes the enzyme reverse transcriptase. The family contains seven genera: DELTARETROVIRUS; LENTIVIRUS; RETROVIRUSES TYPE B, MAMMALIAN; ALPHARETROVIRUS; GAMMARETROVIRUS; RETROVIRUSES TYPE D; and SPUMAVIRUS. A key feature of retrovirus biology is the synthesis of a DNA copy of the genome which is integrated into cellular DNA. After integration it is sometimes not expressed but maintained in a latent state (PROVIRUSES).
An enzyme that synthesizes DNA on an RNA template. It is encoded by the pol gene of retroviruses and by certain retrovirus-like elements. EC
A family of bullet-shaped viruses of the order MONONEGAVIRALES, infecting vertebrates, arthropods, protozoa, and plants. Genera include VESICULOVIRUS; LYSSAVIRUS; EPHEMEROVIRUS; NOVIRHABDOVIRUS; Cytorhabdovirus; and Nucleorhabdovirus.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Small, linear single-stranded RNA molecules functionally acting as molecular parasites of certain RNA plant viruses. Satellite RNAs exhibit four characteristic traits: (1) they require helper viruses to replicate; (2) they are unnecessary for the replication of helper viruses; (3) they are encapsidated in the coat protein of the helper virus; (4) they have no extensive sequence homology to the helper virus. Thus they differ from SATELLITE VIRUSES which encode their own coat protein, and from the genomic RNA; (=RNA, VIRAL); of satellite viruses. (From Maramorosch, Viroids and Satellites, 1991, p143)
The type species of LEPORIPOXVIRUS causing infectious myxomatosis, a severe generalized disease, in rabbits. Tumors are not always present.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
An acute viral infection in humans involving the respiratory tract. It is marked by inflammation of the NASAL MUCOSA; the PHARYNX; and conjunctiva, and by headache and severe, often generalized, myalgia.
A species of ORTHOPOXVIRUS that is the etiologic agent of COWPOX. It is closely related to but antigenically different from VACCINIA VIRUS.
Viruses whose hosts are in the domain ARCHAEA.
A species of ARENAVIRUS, part of the Old World Arenaviruses (ARENAVIRUSES, OLD WORLD), and the etiologic agent of LASSA FEVER. LASSA VIRUS is a common infective agent in humans in West Africa. Its natural host is the multimammate mouse Mastomys natalensis.
Defective viruses which can multiply only by association with a helper virus which complements the defective gene. Satellite viruses may be associated with certain plant viruses, animal viruses, or bacteriophages. They differ from satellite RNA; (RNA, SATELLITE) in that satellite viruses encode their own coat protein.
A species of ORTHOPOXVIRUS causing infections in humans. No infections have been reported since 1977 and the virus is now believed to be virtually extinct.
Proteins found mainly in icosahedral DNA and RNA viruses. They consist of proteins directly associated with the nucleic acid inside the NUCLEOCAPSID.
The type species in the genus NOROVIRUS, first isolated in 1968 from the stools of school children in Norwalk, Ohio, who were suffering from GASTROENTERITIS. The virions are non-enveloped spherical particles containing a single protein. Multiple strains are named after the places where outbreaks have occurred.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A species of ALPHAVIRUS causing an acute dengue-like fever.
A family of small RNA viruses comprising some important pathogens of humans and animals. Transmission usually occurs mechanically. There are nine genera: APHTHOVIRUS; CARDIOVIRUS; ENTEROVIRUS; ERBOVIRUS; HEPATOVIRUS; KOBUVIRUS; PARECHOVIRUS; RHINOVIRUS; and TESCHOVIRUS.
The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.
Inoculation of a series of animals or in vitro tissue with an infectious bacterium or virus, as in VIRULENCE studies and the development of vaccines.
A collection of single-stranded RNA viruses scattered across the Bunyaviridae, Flaviviridae, and Togaviridae families whose common property is the ability to induce encephalitic conditions in infected hosts.
Viral proteins found in either the NUCLEOCAPSID or the viral core (VIRAL CORE PROTEINS).
The quantity of measurable virus in a body fluid. Change in viral load, measured in plasma, is sometimes used as a SURROGATE MARKER in disease progression.
A large genus of plant viruses of the family POTYVIRIDAE which infect mainly plants of the Solanaceae. Transmission is primarily by aphids in a non-persistent manner. The type species is potato virus Y.
Immunoglobulins produced in response to VIRAL ANTIGENS.
The type species of SIMPLEXVIRUS causing most forms of non-genital herpes simplex in humans. Primary infection occurs mainly in infants and young children and then the virus becomes latent in the dorsal root ganglion. It then is periodically reactivated throughout life causing mostly benign conditions.
A defective virus, containing particles of RNA nucleoprotein in virion-like form, present in patients with acute hepatitis B and chronic hepatitis. It requires the presence of a hepadnavirus for full replication. This is the lone species in the genus Deltavirus.
The type species of LYMPHOCRYPTOVIRUS, subfamily GAMMAHERPESVIRINAE, infecting B-cells in humans. It is thought to be the causative agent of INFECTIOUS MONONUCLEOSIS and is strongly associated with oral hairy leukoplakia (LEUKOPLAKIA, HAIRY;), BURKITT LYMPHOMA; and other malignancies.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Infection with human herpesvirus 4 (HERPESVIRUS 4, HUMAN); which may facilitate the development of various lymphoproliferative disorders. These include BURKITT LYMPHOMA (African type), INFECTIOUS MONONUCLEOSIS, and oral hairy leukoplakia (LEUKOPLAKIA, HAIRY).
A suborder of PRIMATES consisting of six families: CEBIDAE (some New World monkeys), ATELIDAE (some New World monkeys), CERCOPITHECIDAE (Old World monkeys), HYLOBATIDAE (gibbons and siamangs), CALLITRICHINAE (marmosets and tamarins), and HOMINIDAE (humans and great apes).
Genotypic differences observed among individuals in a population.
A subgroup of the genus FLAVIVIRUS that causes encephalitis and hemorrhagic fevers and is found in eastern and western Europe and the former Soviet Union. It is transmitted by TICKS and there is an associated milk-borne transmission from viremic cattle, goats, and sheep.
A protein-nucleic acid complex which forms part or all of a virion. It consists of a CAPSID plus enclosed nucleic acid. Depending on the virus, the nucleocapsid may correspond to a naked core or be surrounded by a membranous envelope.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
A family of RNA plant viruses infecting dicotyledons. Transmission is mainly by mechanical inoculation and through propagative plant material. All species elicit formation of multivesicular inclusion bodies. There are at least eight genera: Aureusvirus, Avenavirus, CARMOVIRUS, Dianthovirus, Machlomovirus, Necrovirus, Panicovirus, and TOMBUSVIRUS.
The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.
Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).
A genus in the family TOMBUSVIRIDAE mostly found in temperate regions. Some species infecting legumes (FABACEAE) are reported from tropical areas. Most viruses are soil-borne, but some are transmitted by the fungus Olpidium radicale and others by beetles. Carnation mottle virus is the type species.
Proteins prepared by recombinant DNA technology.
RNA present in neoplastic tissue.
Ribonucleic acid in protozoa having regulatory and catalytic roles as well as involvement in protein synthesis.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
A mosquito-borne species of the PHLEBOVIRUS genus found in eastern, central, and southern Africa, producing massive hepatitis, abortion, and death in sheep, goats, cattle, and other animals. It also has caused disease in humans.
A phenomenon in which infection by a first virus results in resistance of cells or tissues to infection by a second, unrelated virus.
INFLAMMATION of the LIVER in humans caused by HEPATITIS C VIRUS, a single-stranded RNA virus. Its incubation period is 30-90 days. Hepatitis C is transmitted primarily by contaminated blood parenterally, and is often associated with transfusion and intravenous drug abuse. However, in a significant number of cases, the source of hepatitis C infection is unknown.
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
Specific hemagglutinin subtypes encoded by VIRUSES.
The sequence at the 5' end of the messenger RNA that does not code for product. This sequence contains the ribosome binding site and other transcription and translation regulating sequences.
A family of unenveloped RNA viruses with cubic symmetry. The twelve genera include ORTHOREOVIRUS; ORBIVIRUS; COLTIVIRUS; ROTAVIRUS; Aquareovirus, Cypovirus, Phytoreovirus, Fijivirus, Seadornavirus, Idnoreovirus, Mycoreovirus, and Oryzavirus.
A genus of the family PARAMYXOVIRIDAE (subfamily PARAMYXOVIRINAE) where all the virions have both HEMAGGLUTININ and NEURAMINIDASE activities and encode a non-structural C protein. SENDAI VIRUS is the type species.
Macromolecular molds for the synthesis of complementary macromolecules, as in DNA REPLICATION; GENETIC TRANSCRIPTION of DNA to RNA, and GENETIC TRANSLATION of RNA into POLYPEPTIDES.
The type species of ARENAVIRUS, part of the Old World Arenaviruses (ARENAVIRUSES, OLD WORLD), producing a silent infection in house and laboratory mice. In humans, infection with LCMV can be inapparent, or can present with an influenza-like illness, a benign aseptic meningitis, or a severe meningoencephalomyelitis. The virus can also infect monkeys, dogs, field mice, guinea pigs, and hamsters, the latter an epidemiologically important host.
Enzymes that catalyze the hydrolysis of ester bonds within RNA. EC 3.1.-.
Any of the viruses that cause inflammation of the liver. They include both DNA and RNA viruses as well viruses from humans and animals.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
An inheritable change in cells manifested by changes in cell division and growth and alterations in cell surface properties. It is induced by infection with a transforming virus.
The rate dynamics in chemical or physical systems.
A species of CORONAVIRUS causing atypical respiratory disease (SEVERE ACUTE RESPIRATORY SYNDROME) in humans. The organism is believed to have first emerged in Guangdong Province, China, in 2002. The natural host is the Chinese horseshoe bat, RHINOLOPHUS sinicus.
Proteins conjugated with nucleic acids.

Inhibition of Pichinde virus replication by actinomycin D. (1/1788)

The yields of Pichinde virus, a member of the arenavirus group, were markedly inhibited when infected BHK 21 cells were incubated in the presence of 0.4 to 4 mug/ml of actinomycin D. Maximal inhibition was observed when actinomycin D was added after the adsorption of virus to cultures; however, addition of drug as late as 12 h after infection reduced the 24 h yield by 50%. Virus antigen synthesis, as measured by complement fixation and immunodiffusion, was not dramatically reduced by actinomycin D. The expression of virus antigens on the surface of infected cells was greater on cells treated with actinomycin D than on untreated cells. Putative defective particles with a density of Pichinde virus were not detected in fluids of cultures incubated with actinomycin D and 3H-amino acids. Actinomycin D appears to inhibit Pichinde virus late in the replicative cycle. The observations raise the possibility that the drug inhibits the synthesis of proteins of the host cell membrane which are required for virus maturation.  (+info)

Transmission bottlenecks as determinants of virulence in rapidly evolving pathogens. (2/1788)

Transmission bottlenecks occur in pathogen populations when only a few individual pathogens are transmitted from one infected host to another in the initiation of a new infection. Transmission bottlenecks can dramatically affect the evolution of virulence in rapidly evolving pathogens such as RNA viruses. Characterizing pathogen diversity with the quasispecies concept, we use analytical and simulation methods to demonstrate that severe bottlenecks are likely to drive down the virulence of a pathogen because of stochastic loss of the most virulent pathotypes, through a process analogous to Muller's ratchet. We investigate in this process the roles of host population size, duration of within-host viral replication, and transmission bottleneck size. We argue that the patterns of accumulation of deleterious mutation may explain differing levels of virulence in vertically and horizontally transmitted diseases.  (+info)

Sequence of the genomic RNA of nudaurelia beta virus (Tetraviridae) defines a novel virus genome organization. (3/1788)

The monopartite genome of Nudaurelia beta virus, the type species of the Betatetravirus genus of the family Tetraviridae, consists of a single-stranded positive-sense RNA (ss+RNA) of 6625 nucleotides containing two open reading frames (ORFs). The 5' proximal ORF of 5778 nucleotides encodes a protein of 215 kDa containing three functional domains characteristic of RNA-dependent RNA polymerases of ss+RNA viruses. The 3' proximal ORF of 1836 nucleotides, which encodes the 66-kDa capsid precursor protein, overlaps the replicase gene by more than 99% (1827 nucleotides) and is in the +1 reading frame relative to the replicase reading frame. This capsid precursor is expressed via a 2656-nucleotide subgenomic RNA. The 3' terminus of the genome can be folded into a tRNA-like secondary structure that has a valine anticodon; the tRNA-like structure lacks a pseudoknot in the aminoacyl stem, a feature common to both genera of tetraviruses. Comparison of the sequences of Nudaurelia beta virus and another member of the Tetraviridae, Helicoverpa armigera stunt virus, which is in the genus Omegatetravirus, shows identities of 31.6% for the replicase and 24.5% for the capsid protein. The viruses in the genera Betatetravirus and Omegatetravirus of the Tetraviridae are clearly related but show significant differences in their genome organization. It is concluded that the ancestral virus with a bipartite genome, as found in the genus Omegatetravirus, likely evolved from a virus with an unsegmented genome, as found in the genus Betatetravirus, through evolution of the subgenomic RNA into a separate genomic component, with the accompanying loss of the capsid gene from the longer genomic RNA.  (+info)

Multiple mitochondrial viruses in an isolate of the Dutch Elm disease fungus Ophiostoma novo-ulmi. (4/1788)

The nucleotide sequences of three mitochondrial virus double-stranded (ds) RNAs, RNA-4 (2599 nucleotides), RNA-5 (2474 nucleotides), and RNA-6 (2343 nucleotides), in a diseased isolate Log1/3-8d2 (Ld) of the Dutch elm disease fungus Ophiostoma novo-ulmi have been determined. All these RNAs are A-U-rich (71-73% A + U residues). Using the fungal mitochondrial genetic code in which UGA codes for tryptophan, the positive-strand of each of RNAs 4, 5, and 6 contains a single open reading frame (ORF) with the potential to encode a protein of 783, 729, and 695 amino acids, respectively, all of which contain conserved motifs characteristic of RNA-dependent RNA polymerases (RdRps). Sequence comparisons showed that these RNAs are related to each other and to a previously characterized RNA, RNA-3a, from the same O. novo-ulmi isolate, especially within the RdRp-like motifs. However, the overall RNA nucleotide and RdRp amino acid sequence identities were relatively low (43-55% and 20-32%, respectively). The 5'- and 3'-terminal sequences of these RNAs are different, but they can all be folded into potentially stable stem-loop structures. Those of RNA-4 and RNA-6 have inverted complementarity, potentially forming panhandle structures. Their molecular and biological properties indicate that RNAs 3a, 4, 5, and 6 are the genomes of four different viruses, which replicate independently in the same cell. These four viruses are also related to a mitochondrial RNA virus from another fungus, Cryphonectria parasitica, recently designated the type species of the Mitovirus genus of the Narnaviridae family, and to a virus from the fungus Rhizoctonia solani. It is proposed that the four O. novo-ulmi mitochondrial viruses are assigned to the Mitovirus genus and designated O. novo-ulmi mitovirus (OnuMV) 3a-Ld, 4-Ld, 5-Ld, and 6-Ld, respectively. Northern blot analysis indicated that O. novo-ulmi Ld nucleic acid extracts contain more single-stranded (ss, positive-stranded) RNA than dsRNA for all three newly described mitoviruses. O. novo-ulmi RNA-7, previously believed to be a satellite-like RNA, is shown to be a defective RNA, derived from OnuMV4-Ld RNA by multiple internal deletions. OnuMV4-Ld is therefore the helper virus for the replication of both RNA-7 and another defective RNA, RNA-10. Sequence comparisons indicate that RNA-10 could be derived from RNA-7, as previously suggested, or derived directly from RNA-4.  (+info)

Comparative study of viral encephalopathy and retinopathy in juvenile sea bass Dicentrarchus labrax infected in different ways. (5/1788)

The transmission of viral encephalopathy and retinopathy (VER) was investigated in juvenile sea bass (3 g) Dicentrarchus labrax by using cell culture supernatant (SSN-1 cell line) containing nodavirus. Five methods of infection were tested: intramuscular injection (IM), intraperitoneal injection (IP), oral infection, bath exposure and cohabitation of healthy fish with infected fish. Some differences were observed in time of disease onset and severity of symptoms depending on the mode of infection used. Clinical symptoms such as whirling swimming and lethargic or hyperactive behaviour were generally reproduced, except for fish infected via oral and IP infection. First mortalities occurred 3 d after IM and IP infection and 6 d after for the other modes of infection. Cumulative mortalities were also variable: 100% after IM infection, 10% after IP infection, 32% for bath exposure, 43% after cohabitation and 24% via oral infection. Histopathologically, vacuolation was observed in the central nervous tissues and in the retina. The observed lesions were more or less severe depending on the mode of infection, the sampling time and the organs: lesions on the surviving fish (42 days post infection, d p.i.) seemed to be generally more conspicuous in the retina than in the brain of the same fish. In most cases, the presence of nodavirus was confirmed in the same samples of brain and retina by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). The virus was not detected in other organs examined. The present results suggest that 2 forms of VER can be induced: IM injection leads to an acute form (severe nervous disorders with high and fast mortality) whereas oral infection, bath exposure and cohabitation induce a subacute form (less severe disorders and weak daily mortality). This experiment demonstrates experimentally induced horizontal transmission of VER in sea bass for the first time.  (+info)

Structural constraints on RNA virus evolution. (6/1788)

The recently discovered hepatitis G virus (HGV) or GB virus C (GBV-C) is widely distributed in human populations, and homologues such as HGV/GBV-CCPZ and GBV-A are found in a variety of different primate species. Both epidemiological and phylogenetic analyses support the hypothesis that GB viruses coevolved with their primate hosts, although their degree of sequence similarity appears incompatible with the high rate of sequence change of HGV/GBV-C over short observation periods. Comparison of complete coding sequences (8,500 bases) of different genotypes of HGV/GBV-C showed an excess of invariant synonymous sites (at 23% of all codons) compared with the frequency expected by chance (10%). To investigate the hypothesis that RNA secondary-structure formation through internal base pairing limited sequence variability at these sites, an algorithm was developed to detect covariant sites among HGV/GBV-C sequences of different genotypes. At least 35 covariant sites that were spatially associated with potential stem-loop structures were detected, whose positions correlated with positions in the genome that showed reductions in synonymous variability. Although the functional roles of the predicted secondary structures remain unclear, the restriction of sequence change imposed by secondary-structure formation provides a mechanism for differences in net rate of accumulation of nucleotide substitutions at different sites. However, the resulting disparity between short- and long-term rates of sequence change of HGV/GBV-C violates the assumptions of the "molecular clock." This places a major restriction on the use of nucleotide or amino acid sequence comparisons to calculate times of divergence of other viruses evolving under the same structural constraints as GB viruses.  (+info)

A highly membrane-active peptide in Flock House virus: implications for the mechanism of nodavirus infection. (7/1788)

BACKGROUND: Nodaviruses are among the simplest animal viruses, and are therefore attractive systems for deconvoluting core viral processes such as assembly, infection and uncoating. Membrane translocation of the single-stranded RNA genome of nodaviruses has been proposed to be mediated by direct lipid-protein interactions between a post-assembly autocatalytic cleavage product from the capsomere and the target membrane. To probe the validity of this hypothesis, we have synthesized a 21-residue Met-->Nle (norleucine) variant of the amino-terminal helical domain (denoted here as gamma1) of the cleavage peptide in Flock House nodavirus (FHV) and studied its ability to alter membrane structure and function. RESULTS: The synthetic peptide gamma1 increases membrane permeability to hydrophilic solutes, as judged by fluorescence experiments with liposome-encapsulated dyes and ion-conductance measurements. Furthermore, peptide orientation and location within lipid bilayers was determined using tryptophan-fluorescence-quenching experiments and attenuated total reflectance infrared spectroscopy. CONCLUSIONS: The helical domain of the FHV cleavage product partitions spontaneously into lipid bilayers and increases membrane permeability, consistent with the postulated mechanism for viral genome translocation. The existence of a membrane-binding domain in the FHV cleavage sequence suggests peptide-triggered disruption of the endosomal membrane as a prelude to viral uncoating in the host cytoplasm. A model for this interaction is proposed.  (+info)

Transmission of viral encephalopathy and retinopathy (VER) to yolk-sac larvae of the Atlantic halibut Hippoglossus hippoglossus: occurrence of nodavirus in various organs and a possible route of infection. (8/1788)

The susceptibility of the Atlantic halibut Hippoglossus hippoglossus yolk-sac larvae to viral encephalopathy and retinopathy (VER) was investigated by waterborne challenge experiments with nodavirus. Transfer of VER was indicated by several lines of evidence. A significantly higher cumulative mortality was observed after challenge with virus compared to mock challenge, and increasing doses of virus resulted in shorter incubation periods. When the challenge was performed on the day after hatching, the time from inoculation to the time when 50% of the larvae were dead (LT50) ranged from 26 to 32 d. Postponement of challenge for 13 d reduced the LT50 to 14 d, indicating that the susceptibility of the larvae to the present nodavirus strain was low during the first 2 wk after hatching. The progression of the infection was monitored by sequential immunohistochemistry and electron microscopy. On Day 18 after hatching the initial signs of infection were observed as a prominent focus of immunolabelling in the caudal part of the brain stem. In the same larvae immunolabelled single cell lesions were observed in the stratified epithelium of the cranial part of the intestine. The portal of entry into the larvae may thus have been the intestinal epithelium, while the route of infection to the CNS may have been axonal transport to the brain stem through cranial nerves such as the vagus nerves. Later in the infection, lesions became more severe and widespread and were also found throughout the brain and spinal cord and in the retina, cranial ganglia, intestine, liver, olfactory epithelium, yolk-sac epithelium, gills and pectoral fins. The mortality in all virus-challenged groups was 100%. This study thus demonstrates that the present nodavirus strain is able to replicate and cause VER in Atlantic halibut yolk-sac larvae at temperatures as low as 6 degrees C.  (+info)

Sacbrood virus (SBV) and deformed wing virus (DWV) are evolutionarily related positive-strand RNA viruses, members of the Iflavirus group, which infect the honeybee Apis mellifera, but have strikingly different levels of virulence when transmitted orally. Honeybee larvae orally infected with SBV usually accumulate high levels of the virus, which halts larval development and causes insect death. In contrast, oral DWV infection at the larval stage usually causes asymptomatic infection with low levels of the virus, although high doses of ingested DWV could lead to DWV replicating to high levels. We investigated effects of DWV and SBV infection on the transcriptome of honeybee larvae and pupae using global RNA-Seq and real-time PCR analysis. This showed that high levels of SBV replication resulted in down-regulation of the genes involved in cuticle and muscle development, together with changes in expression of putative immune-related genes. In particular, honeybee larvae with high levels of SBV ...
A negative-sense single-stranded RNA virus (or (-)ssRNA virus) is a virus that uses negative sense, single-stranded RNA as its genetic material. Single stranded RNA viruses are classified as positive or negative depending on the sense or polarity of the RNA. The negative viral RNA is complementary to the mRNA and must be converted to a positive RNA by RNA polymerase before translation. Therefore, the purified RNA of a negative sense virus is not infectious by itself, as it needs to be converted to a positive sense RNA for replication. These viruses belong to Group V on the Baltimore classification. In addition, negative-sense single-stranded RNA viruses have complex genomic sequences, cell cycles, and replication habits that use various protein complexes to arrange in specific conformations and carry out necessary processes for survival and reproduction of their genomic sequences. The complexity of negative-sense single-stranded RNA viruses carries into its ability to suppress the innate immune ...
A positive-sense single-stranded RNA virus (or (+)ssRNA virus) is a virus that uses positive sense, single-stranded RNA as its genetic material. Single stranded RNA viruses are classified as positive or negative depending on the sense or polarity of the RNA. The positive-sense viral RNA genome can also serve as messenger RNA and can be translated into protein in the host cell. Positive-sense ssRNA viruses belong to Group IV in the Baltimore classification. Positive-sense RNA viruses account for a large fraction of known viruses, including many pathogens such as the hepatitis C virus, West Nile virus, dengue virus, and SARS and MERS coronaviruses, as well as less clinically serious pathogens such as the rhinoviruses that cause the common cold. Positive-sense ssRNA viruses have genetic material that can function both as a genome and as messenger RNA; it can be directly translated into protein in the host cell by host ribosomes. The first proteins to be expressed after infection serve genome ...
Hepatitis C trojan (HCV) is an enveloped, positive strand RNA computer virus of about 9. attributable to inherently different properties of low density particles, to association of these particles with factors stimulating fusion, or to co-floatation of factors enhancing fusion activity in genus of the Flaviviridae family (1). Based on sequence comparison, patient isolates are classified into seven genotypes, differing in their nucleotide sequence by 30C35% (2C5). The two viral surface proteins, E1 (residues 192C383) and E2 (residues 384C746), are processed by transmission peptidases of the endoplasmic reticulum from a 3,000-amino acid-long polyprotein encoded by the HCV genome (examined in Ref. 2). The E1 (31 kDa) and E2 (70 kDa) proteins are glycosylated in their large amino-terminal ectodomains (6) and are anchored in the viral membrane by their carboxyl-terminal transmembrane domains. E1 and E2 form a heterodimer stabilized by noncovalent interactions. This oligomer is usually thought to be ...
Summary of Facts and Submissions. I. European patent No. 0 846 181 with the title cDNA corresponding to the antigenome of nonsegmented negative strand RNA viruses, and process for the production of such viruses encoding additional antigenically active proteins was granted on European patent application No. 96928446.2 (published as WO 97/06270). The patent was granted with 21 claims.. II. Claim 1 of the patent as granted read as follows:. 1. A method for the production of an infectious non-segmented negative-strand RNA virus of the family Paramyxoviridae comprising. (a) introducing a cDNA molecule contained in a plasmid, wherein said cDNA molecule comprises the entire (+)-strand sequence of said negative- strand RNA virus operatively linked to an expression control sequence, which allows the synthesis of anti-genomic RNA transcripts bearing the authentic 3 -termini, and wherein said cDNA molecule consists of an integral multiple of six nucleotides, into a helper cell expressing an ...
The great variety of genome organizations means that most plant positive strand viral RNAs differ from the standard 5-cap/3-poly(A) structure of eukaryotic mRNAs. The cap and poly(A) tail recruit initiation factors that support the formation of a closed loop mRNA conformation, the state in which translation initiation is most efficient. We review the diverse array of cis-acting sequences present in viral mRNAs that compensate for the absence of a cap, poly(A) tail, or both. We also discuss the cis-acting sequences that control translation strategies that both amplify the coding potential of a genome and regulate the accumulations of viral gene products. Such strategies include leaky scanning initiation of translation of overlapping open reading frames, stop codon readthrough, and ribosomal frameshifting. Finally, future directions for research on the translation of plant positive strand viruses are discussed.. ...
Zika Virus Ns5 Monoclonals Zika Virus Reagents Research Reagents Biofront Technologies. Zika virus is a single positive strand RNA virus with a genome that encodes three structural proteins and seven non-structural (NS) proteins: NS1, NS2A, NS2B, NS3, NS4A, NS4B and NS5. The flavivirus NS5 protein is the largest of the NS proteins and possesses enzymatic activities required for the synthesis of the 11 kb viral RNA genome, making it essential for replication and a prime target for drug candidates. Zika NS5 Mab 6A1 100 ug Zika NS5 Mab 6A1 500 ug Zika NS5 Mab 6A1 1 mg Zika NS5 Mab 8B8 100 ug Zika NS5 Mab 8B8 500 ug Zika NS5 Mab 8B8 1 mg Zika NS5 Mab 7A9 100 ug Zika NS5 Mab 7A9 500 ug Zika NS5 Mab 7A9 1mg
In the summer of 2005, Giau was a REU intern in Dr. C. Kaos lab at Texas A&M University. Her project was titled, Visualization of Fluorescent Brome Mosaic Virus RNA3 in an In-vivo Environment.. During my stay at Texas, I worked with a plant virus called Brome Mosaic Virus. In recent years, this virus has become a model system for positive strand RNA viruses.. The internship was a rewarding experience because it was my first time being exposed to scientific research on a larger scale. Within one lab there were at least 4-5 large scale projects going on. It was definately an action-packed environment for science majors.. Secondly, I was very amazed to see how these scientists were so dedicated to their work. The Post-doc that I worked under spent at least 12 hours a day in the lab during weekdays, and he was always in the lab on the weekends as well. Through this internship I found out that the lab is where I want to be in the future.. Giau graduated magna cum laude with a double major in ...
2nd International Symposium on Positive Strand RNA Viruses. Vienna, Austria, 26-30 June 1989. Topics include: Genome Replication; DI-RNAs and Vectors; Protein Translation, Cleavage and Modification; Virion Structure and Assembly; Antigenic Structure; Virus Receptors, Uptake and Disassembly; Pathogenesis and Virulence; Strategies for Control of Viral Disease; Viral Evolution. Satellite meeting 24-25 June 1989: World Health Organization Review on the development of dengue, Japanese encephalitis and other flavivirus vaccines. Contact: Dr F. X. Heinz; Institute of Virology; Kinderspitalgasse 15; A-1095 Vienna; Austria; Tel. no. (area code 222) 43 15 95; Fax no. (area code 222) 43 21 61
Next-generation sequencing is a valuable tool in our growing understanding of the genetic diversity of viral populations. Using this technology, we have investigated the RNA content of a purified nonenveloped single-stranded RNA virus, flock house virus (FHV). We have also investigated the RNA content of virus-like particles (VLPs) of FHV and the related Nudaurelia capensis omega virus. VLPs predominantly package ribosomal RNA and transcripts of their baculoviral expression vectors. In addition, we find that 5.3% of the packaged RNAs are transposable elements derived from the Sf21 genome. This observation may be important when considering the therapeutic use of VLPs. We find that authentic FHV virions also package a variety of host RNAs, accounting for 1% of the packaged nucleic acid. Significant quantities of host messenger RNAs, ribosomal RNA, noncoding RNAs, and transposable elements are readily detected. The packaging of these host RNAs elicits the possibility of horizontal gene transfer ...
Single-stranded RNA viruses have evolved to survive extremely high mutation rates.The ubiquity and effect of ssRNA viral diseases makes an understanding of the theoretical and mechanical underpinnings of rapid viral evolution vital to our ability to control them. In this body of work, we explore some of the ways in which ssRNA viruses can uncouple the rate at which variation is generated (mutation rate) from the rate at which variation is observed (measured rate of molecular evolution).. ...
RNA viruses have been isolated that infect marine organisms ranging from bacteria to whales, but little is known about the composition and population structure of the in situ marine RNA virus community. In a recent study, the majority of three genomes of previously unknown positive-sense single-stranded (ss) RNA viruses were assembled from reverse-transcribed whole-genome shotgun libraries. The present contribution comparatively analyzes these genomes with respect to representative viruses from established viral taxa. Two of the genomes (JP-A and JP-B), appear to be polycistronic viruses in the proposed order Picornavirales that fall into a well-supported clade of marine picorna-like viruses, the characterized members of which all infect marine protists. A temporal and geographic survey indicates that the JP genomes are persistent and widespread in British Columbia waters. The third genome, SOG, encodes a putative RNA-dependent RNA polymerase (RdRp) that is related to the RdRp of viruses in the family
RNA virus replication machineries.(A) RdRps of hepatitis C virus and reovirus. Hepatitis C virus is a (+)RNA virus from the Flaviviridae family, while reovirus
Single stranded RNA (ssRNA) viruses are an incredibly diverse viral group capable of infecting plants and animals. Common ssRNA viruses causing human disease are picornaviridae (rhinovirus [the common cold], polio), coronoaviridae (SARS, MERS), and filoviridae (Ebola, Marburg). Positive ssRNA viruses have their genetic material directly translated into usable proteins, while negative ssRNA viruses use an RNA replicase enzyme to convert their genetic material to positive strands before being used to make proteins. As evidenced by the efficacy of the seasonal flu vaccine and the ongoing trials for an Ebola cure, pharmacological interventions to cure a ssRNA infection are few and far between.. Now, years after original research was published on ssRNA packaging within a cell, the English researchers have shown that viral RNA induces conformational changes in capsid proteins, essentially telling the viral packaging it is ready to bud from the infected cell. Previous research from this group showed ...
Most RNA viruses infecting mammals and other vertebrates show profound suppression of CpG and UpA dinucleotide frequencies. To investigate this functionally, mutants of the picornavirus, echovirus 7 (E7), were constructed with altered CpG and UpA compositions in two 1.1-1.3 Kbase regions. Those with increased frequencies of CpG and UpA showed impaired replication kinetics and higher RNA/infectivity ratios compared with wild-type virus. Remarkably, mutants with CpGs and UpAs removed showed enhanced replication, larger plaques and rapidly outcompeted wild-type virus on co-infections. Luciferase-expressing E7 sub-genomic replicons with CpGs and UpAs removed from the reporter gene showed 100-fold greater luminescence. E7 and mutants were equivalently sensitive to exogenously added interferon-β, showed no evidence for differential recognition by ADAR1 or pattern recognition receptors RIG-I, MDA5 or PKR. However, kinase inhibitors roscovitine and C16 partially or entirely reversed the attenuated phenotype of
Characterizing the genome of mature virions is pivotal to understanding the highly dynamic processes of virus assembly and infection. Owing to the different cellular fates of DNA and RNA, the life cycles of double-stranded (ds)DNA and dsRNA viruses are dissimilar. In terms of nucleic acid packing, dsDNA viruses, which lack genome segmentation and intra-capsid transcriptional machinery, predominantly display single-spooled genome organizations1-8. Because the release of dsRNA into the cytoplasm triggers host defence mechanisms9, dsRNA viruses retain their genomes within a core particle that contains the enzymes required for RNA replication and transcription10-12. The genomes of dsRNA viruses vary greatly in the degree of segmentation. In members of the Reoviridae family, genomes consist of 10-12 segments and exhibit a non-spooled arrangement mediated by RNA-dependent RNA polymerases11-14. However, whether this arrangement is a general feature of dsRNA viruses remains unknown. Here, using cryo-electron
RNA viruses exploit all known mechanisms of genetic variation to ensure their survival. Distinctive features of RNA virus replication include high mutation rates, high yields, and short replication times. As a consequence, RNA viruses replicate as complex and dynamic mutant swarms, called viral quas …
By the analysis of thermodynamic RNA secondary structure predictions, we previously obtained evidence for evolutionarily conserved large-scale ordering of RNA virus genomes (P. Simmonds, A. Tuplin, and D.J. Evans, RNA 10: 1337-1351, 2004). Genome-scale ordered RNA structure (GORS) was widely distributed in many animal and plant viruses, much greater in extent than RNA structures required for viral translation or replication, but in mammalian viruses was associated with host persistence. To substantiate the existence of large-scale RNA structure differences between viruses, a large set of alignments of mammalian RNA viruses and rRNA sequences as controls were examined by thermodynamic methods (to calculate minimum free energy differences) and by algorithmically independent RNAz and Pfold methods. These methods produced generally concordant results and identified substantial differences in the degrees of evolutionarily conserved, sequence order-dependent RNA secondary structure between virus ...
role of rna-protein interactions in the internal initiation of translation of plus-strand rna viruses : a novel target for antiviral therapeutics
Genome RNA replication of all (+)RNA viruses takes place in close association with rearranged intracellular membranes. We are only beginning to understand the biogenesis and ultrastructure of these virus-induced membrane structures. In collaboration with the virology groups of LUMC (Prof. Dr. Eric Snijder) and the University of Utrecht (Prof. Dr. Frank van Kuppeveld), EM and tomography approaches will be used to gain more insight into the architecture of the rearranged membranes, the localization of the viral replication enzymes, and the localization of host factors that are hijacked by picornavirus to facilitate replication of their RNA genome.. Host institute ...
RNA viruses generally have very high mutation rates as they lack DNA polymerases which can find and fix mistakes, and are therefore unable to conduct DNA repair of damaged genetic material. DNA viruses have considerably lower mutation rates due to the proof-reading ability of DNA polymerases within the host cell. Retroviruses integrate a DNA intermediate of their RNA genome into the host genome, and therefore have a higher chance of correcting any mistakes in their genome thanks to the action of proof-reading DNA polymerases belonging to the host cell. Although RNA usually mutates rapidly, recent work found that the SARS virus and related RNA viruses contain a gene that mutates very slowly.[4] The gene in question has a complex three-dimensional structure which is hypothesized to provide a chemical function necessary for viral propagation, perhaps as a ribozyme. If so, most mutations would render it unfit for that purpose and would not propagate. ...
RNA viruses generally have very high mutation rates as they lack DNA polymerases which can find and fix mistakes, and are therefore unable to conduct DNA repair of damaged genetic material. DNA viruses have considerably lower mutation rates due to the proof-reading ability of DNA polymerases within the host cell. Retroviruses integrate a DNA intermediate of their RNA genome into the host genome, and therefore have a higher chance of correcting any mistakes in their genome thanks to the action of proof-reading DNA polymerases belonging to the host cell. Although RNA usually mutates rapidly, recent work found that the SARS virus and related RNA viruses contain a gene that mutates very slowly.[4] The gene in question has a complex three-dimensional structure which is hypothesized to provide a chemical function necessary for viral propagation, perhaps as a ribozyme. If so, most mutations would render it unfit for that purpose and would not propagate. ...
RNA viruses replicate with low fidelity due to the error-prone nature of the RNA-dependent RNA polymerase, which generates approximately one mutation per round of genome replication. Due to the large population sizes produced by RNA viruses during replication, this results in a cloud of closely related virus variants during host infection, of which small increases or decreases in replication fidelity have been shown to result in virus attenuation in vivo, but not typically in vitro. Since the discovery of the first RNA virus fidelity mutants during the mid-aughts, the field has exploded with the identification of over 50 virus fidelity mutants distributed amongst 7 RNA virus families. This review summarizes the current RNA virus fidelity mutant literature, with a focus upon the definition of a fidelity mutant as well as methods to confirm any mutational changes associated with the fidelity mutant. Due to the complexity of such a definition, in addition to reports of unstable virus fidelity ...
Previously, I have argued that in order to understand the origin of RNA viruses, it is imperative to completely ignore the mainstream view that a major part of our genome is made of the genetic debris of ancient inva-sions of RNA viruses. Instead, I have hypothesized that transposable and transposed elements might have been originally designed to generate variation in offspring and should therefore be renamed variation-and-integrity assuring genetic elements (short: VIGEs). Hence, the major part of genomes contains VIGEs and their degenerate remnants. As mentioned above, ERVs are mobile genetic elementscharacterized by gag and pol genes that closely resemble full-blown RNA viruses, such as influenza and human immunodeficiency viruses. The origin of such RNA viruses can therefore be understood as a transformed ERV. In other words, RNA viruses may form in genomes from gag-pol elements. Gag-pol elements may trans-mute into RNA viruses through sequential uptake and/or recombination of genomic ...
Print this page. or cell membrane- Non-cellular. 2. About 5 percent of the length of the virion is depicted. Average Virus 0.1 m m= 100 nm. Principles of Classification and Nomenclature ... II. Claude MUVUNYI M.D., Ph.D. Terminology. Eg. All pro- Last modified 18/02/2015. VIRUS STRUCTURE AND CLASSIFICATION. Tobacco necrosis virus. Baculovirus, Sacbrood virus, Entomopox virus, Granulosis virus . There are many different types of viruses, and many ways of classifying these. Structure of Influenza virus Influenza virion are usually spherical (diameter 80-110 nm). Structure 4. 2.1 - Taxonomic Classification Meaning of Viruses 2. nucleus, no . Structure. # NA is a target of the antiviral drugs Tamiflu 16. The external surface is ridged in parallel rows, sometimes arranged helically (Fig. Meaning and History of Viruses 2. Dimitri Ivanowski, a Russian botanist in 1892 demonstrated experimentally that sap […] The genome structure system classifies both viruses as single-stranded RNA viruses with ...
Zika virus, computer illustration. This is an RNA (ribonucleic acid) virus from the Flaviviridae family. It is transmitted to humans via the bite of an infected Aedes sp. mosquito. It causes zika fever, a mild disease with symptoms including rash, joint pain and conjunctivitis. In 2015 a previously unknown connection between Zika infection in pregnant women and microcephaly (small head) in newborns was reported. This can cause miscarriage or death soon after birth, or lead to developmental delays and disorders. - Stock Image F012/9109
Several factors play a role during the replication and transmission of RNA viruses. First, as a consequence of their enormous mutation rate, complex mixtures of genomes are generated immediately after infection of a new host. Secondly, differences in growth and competition rates drive the selection of certain genetic variants within an infected host. Thirdly, but not less important, a random sampling occurs at the moment of viral infectious passage from an infected to a healthy host. In addition, the availability of hosts also influences the fate of a given viral genotype. When new hosts are scarce, different viral genotypes might infect the same host, adding an extra complexity to the competition among genetic variants. We have employed a two-fold approach to analyse the role played by each of these factors in the evolution of RNA viruses. First, we have derived a model that takes into account all the preceding factors. This model employs the classic Lotka-Volterra competition equations but it ...
RNA viruses provide unique insights into the patterns and processes of evolutionary change in real time. The study of viral evolution is especially topical given the growing awareness that emerging and re-emerging diseases (most of which are caused by RNA viruses) represent a major threat to public health.
Students working in pairs or small groups receive a simulated virus: two paper cups taped together, enclosing a strip of paper listing an RNA or DNA sequence (an abbreviated viral genome). The students break open the cups (simulating viral uncoating in the host cell) and decide how host and/or viral enzymes will convert the genome into viral proteins and new genomes. The sequences provided describe a double-stranded DNA virus, single-stranded RNA viruses (+ or - strand), a retrovirus, and a double-stranded RNA virus. Templates for photocopying the genomes, sample worksheets, and an instructors answer key are included.
Preface. .. Part I: What is a virus?:.. 1. Towards a Definition of a Virus.. 2. Some Methods for Studying Animal Viruses.. 3. The Structure of Virus Particles.. 4. Classification of Viruses.. Part II: Virus Growth in Cells:.. 5. The Process of Infection: I. Attachment of Viruses and the Entry of Their Genomes into the Target Cell.. 6. The Process of Infection: IIA. The Replication of Viral DNA.. 7. The Process of Infection: IIB. Genome Replication in RNA Viruses.. 8. The Process of Infection: IIC. The Replication of RNA Viruses with a DNA Intermediate and Vice Versa.. 9. The Process of Infection: IIIA. Gene Expression in DNA Viruses and Reverse-Transcribing Viruses.. 10. The Process of Infection: IIIB. Gene Expression and its Regulation in RNA Viruses.. 11. The Process of Infection: IV. The Assembly of Viruses.. Part III: Virus Interactions with the Whole Organism:.. 12. The Immune System and Virus Neutralization.. 13. Interactions Between Animal Viruses and Cells.. 14. Animal Virus-Host ...
InterPro provides functional analysis of proteins by classifying them into families and predicting domains and important sites. We combine protein signatures from a number of member databases into a single searchable resource, capitalising on their individual strengths to produce a powerful integrated database and diagnostic tool.
Viruses impact nearly all organisms on Earth, with ripples of influence in agriculture, health, and biogeochemical processes. However, very little is known about RNA viruses in an environmental context, and even less is known about their diversity and ecology in soil, 1 of the most complex microbial …
Study RNA viruses flashcards from Anthos Christofides's class online, or in Brainscape's iPhone or Android app. ✓ Learn faster with spaced repetition.
two. a pc code that may be inserted right into a application to damage data or bring about glitches. virus فيروس في الكومبيوتر комп. вирус vírus virus der Virus virus ιός Η/Υ virus arvutiviirus ویروس virus virusוירוס वाइरस, विषाणु virus (računalni) számítógépes vírus virus komputer virus コンピューターウイルス 컴퓨터 바이러스 (kompiuterio) virusas datorvīruss virus virusvirus wirus komputerowy زهر вирус počítačový vírus virus virus datavirus ไวรัสคอมพิวเตอร์ virüs 電腦病毒 вірус وائرس، کمپيوٹر نظام کو تباہ کرنے والا کوڈ vi rút máy tính 计算机病 ...
The external surface of some viruses that infect fungi have unanticipated enzyme activity. This is the conclusion of a study published in the journal...
About 95 per cent of us are infected with the Epstein-Barr virus. Cancer Virus is the compelling, thriller-like tale of its discovery
Viruses are small, self-replicating nucleic acid/protein aggregates that depend on the metabolism of their host cell for replication. Viruses do not have their own metabolism; it is thus a question whether viruses can be considered a life form. The genome of a virus can be single- or double-stranded DNA or RNA. Viruses can have a very simple structure and may consist of only a nucleic acid with a protein shell (capsid) for protection. Some viruses pathogenic to animals have a more complex structure: their capsid is surrounded by a membrane made of lipids and glycoproteins that originates in the membrane of the host cell. Viruses that multiply in bacteria are called bacteriophages.. In humans, viruses cause many diseases, including measles, mumps, rubella, chicken pox, rabies, hepatitis, or influenza; some cancers are also related to viral infections (e.g. papilloma viruses). There are vaccines against some of these diseases; the use of antibiotics does not help against viruses. ...
The virus family Flaviviridae encompasses several viruses, including (re)emerging viruses which cause widespread morbidity and mortality throughout the world. Members of this virus family are positive-strand RNA viruses and replicate their genome in close association with reorganized intracellular host cell membrane compartments. ...
Personally I think this may be a bit too curmudgeony. The campaign clearly had the desired effect by showing, well, that microbes can grow fast. So the microbes they used were not viruses. And so the ones they used were not harmful. It still is creepy in a way. It is a fine balance of course. We (the royal we here) want to promote microbes as being fun. And we also want to promote them as not always being dangerous. But microbes also do kill a lot of people. And this billboard will probably do more to get people talking and thinking about bacteria and mold than any other movie promotion in recent memory ...
First of all, cold and flu viruses are not simple viruses, and they are not harmless. They kill tens to hundreds of thousands of people every year. Secondly, this would depend highly on the risk group that the virus falls in. The NIH sets strict guidelines on who can handle infectious agents. Unfortunately, I can almost guarantee you that no one is going to give you even risk group 1 plant viruses, and they are certainly are not going to give you cold or flu viruses. Risk groups range from 1 to 4. To handle risk group 2 viruses, for example, you are expected to do so in a BSL-2 or higher laboratory, and anyone maintaining stocks of virus is going to do a hefty check of you and your facilities before shipping you anything.. Furthermore, even if you did obtain the virus, you would need to store it or maintain stocks of the virus in tissue culture. Its not like you can just get an eppendorf tube of virus in saline and expect it to survive in your refrigerator at home, and its not like companies ...
For more information about how parvo affects dogs, visit worst outbreak in memory of a fatal dog disease has forced the Orange County animal-control department to
Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2. Topic Last Modified: 2012-07-23. You can use the Edge Rules agent and transport rules in Microsoft Exchange Server 2010 to help protect your organization from viruses.. New viruses threaten organizations every day. To minimize the damage caused by viruses, antivirus vendors and administrators must respond to virus threats as soon as possible. Despite a quick response, there will be a gap between the time that a virus threat appears and the time that a solution becomes available. This gap, when a virus threat remains unknown and unresolved, is called a zero-day virus threat. At the same time, viruses that have been circulating on the Internet for many years also continue to pose a significant threat to organizations. Although the majority of these viruses can be identified by antivirus scanners, antivirus scanners may be taken offline by mistake, updated with out-of-date definitions, or experience other problems that make them ...
In article ,m0tedkN-0003SzC at, ED at MOLBIOL.UCT.AC.ZA (Ed Rybicki) writes: , Perhaps the simple inclusion of Luria et al.s qualifier - , ...potentially pathogenic - serves to distinguish them adequately. , , (As in: Viruses have been defined as [potentially pathogenic] , entities whose genomes are elements of nucleic acid that replicate , inside living cells using the cellular synthetic machinery, and cause , the synthesis of specialised elements [virions] that can transfer the , genome to other cells S Luria et al., Virology, 3rd Edn) , What does pathogenic mean? Does this mean that plant cryptic viruses (which seem to cause no symptoms in their hosts) are not viruses? How about the various fungal viruses (such as the hypovirulence associated virus from the chestnu blight fungus) which dont have protein coats and are not transmitted extracellularly? I think that there are a number of things which are quite hard to put into human defined catagories.... Ethan ...
AJ Boulay ,aj.boulay at, wrote: ,As a student of biology, I am curious about the replication and ,classification of viruses. , ,I understand that viruses are inert until they infect a host, that they ,do not undergo replication or division, etc. , ,This leads to my question: How then do viruses proliferate? I can see an ,infected cell within the host replicating, but is this infected cell ,considered a virus? With this in mind, can viruses be classified as an ,organism at any time in thier life cylce? The virus is a free entity until it infects a host. I was correcting a professor last week when she called viruses organisms but I failed to come up with a suitable term to refer to them by. Calling them organisms is just for lack of better terminology. When a virus has infected an organism and is replicating, it can be considered alive and is classified as an organism. Viruses replicate using the machinery in the host organism. All the components of the progeny are assembled by the ...
A virus consists of a protein mantle that encapsulates a strand of DNA or RNA, either single-stranded or double-stranded. The DNA or RNA is injected into a cell nucleus, where the machinery of the cell takes the code and produces many more copies of the virus. These copies break out of the cell and each may go on to infect another cell and repeat the process. Some infections are benign to the cell and organism, while some cause rapid cell death and serious disease. Virus particles can be released from the host cell either by budding of the phospholipid membrane or by traumatic lysing. It is assumed that viral infection occurs passively, with the virus pathogen being delivered to its preferred host by Brownian motion and natural circulatory and behavioral processes of the organism. It is difficult, however, to observe a virus in situ due to the limitations of modern microscopes. Viruses are very small, with a typical size between 40 and 100 nm (1 nm = 10-9 m, nm=nanometer). The term virus ...
Although it is a single-stranded RNA virus, it does mutate to some extent, but it doesnt look like its going to mutate away from the vaccine.
Among the diverse strategies used by viruses to induce human disease, their ability to cause immune defects has received increasing attention, concurrently with the identification of cells able to...
usr/bin/perl -w use strict; my $gCurRec; foreach(qw(name to file action virus)) { $gCurRec-,{$_}=; } while(,DATA,) { $gCurRec-,{name}=$1 if (/^From:\s*(.+?)\s*$/); $gCurRec-,{to}=$1 if (/^To:\s*(.+?)\s*$/); $gCurRec-,{file}=$1 if (/^File:\s*(.+?)\s*$/); $gCurRec-,{action}=$1 if (/^Action:\s*(.+?)\s*$/); $gCurRec-,{virus}=$1 if (/^Virus:\s*(.+?)\s*$/); if (/^-----/) { print $gCurRec-,{name},\t, $gCurRec-,{to},\t, $gCurRec-,{file},\t, $gCurRec-,{action},\t, $gCurRec-,{virus},\n; foreach(qw(name to file action virus)) { $gCurRec-,{$_}=; } } } __DATA__ From: [email protected] To: [email protected] File: value.scr Action: The uncleanable file is deleted. Virus: WORM_KLEZ.H ---------------------------------- Date: 06/30/2002 00:01:21 From: [email protected] To: [email protected] File: Nr.pif Action: The uncleanable file is deleted. Virus: WORM_KLEZ.H ...
Genome replication in picornaviruses is catalyzed by a virally encoded RNA-dependent RNA polymerase, termed 3D. These viruses also use a small protein primer, named VPg, to initiate RNA replication. The recent explosion of structural information on picornaviral 3D polymerases has provided insights into the initiation of RNA synthesis and chain elongation. Comparing these data with results from previous structural analyses of viral RNA-dependent RNA polymerases that catalyze de novo RNA synthesis sheds light on the different strategies that these viruses use to initiate replication. © 2006 Elsevier Ltd. All rights reserved ...
J Jordan Steel, Brian J Geiss, (2015) A Novel System for Visualizing Alphavirus Assembly. Journal of virological methods.. N. L. Sweeney, A. M. Hanson, S. Mukherjee, J. Ndjomou, B. J. Geiss, J. J. Steel, K. J. Frankowski, F. J. Schoenen, D. N. Frick (2015) Benzothiazole and pyrrolone flavivirus inhibitors targeting the viral helicase. ACS Infectious Diseases.. K. M. Bullard, R. C. Gullberg, E. Soltani, J. J. Steel, B. J. Geiss, S. Keenan (2015) Murine Efficacy and Pharmacokinetic Evaluation of the Flaviviral NS5 Capping Enzyme 2-thioxothiazolidin-4-one Inhibitor BG-223. PLoS ONE.. J. J. Steel, R. C. Gullberg, E. Soltani, B. J. Geiss, (2014) Oxidative Stress Influences Positive Strand RNA Virus Genome Synthesis and Capping. Virology.. J. J. Steel, A.W.E. Franz, I. Sanchez-Vargas, K. E. Olson, B. J. Geiss, (2013) Subgenomic Reporter RNA System for Detection of Alphavirus Infection in Mosquitoes. PLoS ONE.. J. J. Steel, B. R. Henderson, S. B. Lama, K. E. Olson, and B. J. Geiss, (2011) Infectious ...
Hypovirulent isolates of the fruit tree fungal pathogen Diaporthe ambigua have previously been shown to harbour a double-stranded (ds)RNA genetic element of about 4 kb. In this study, we established the complete cDNA sequence of this dsRNA, which represents a replicative form of a positive-strand RNA virus that we have named D. ambigua RNA virus (DaRV). The nucleotide sequence of the genome is 4113 bp and has a GC content of 53%. Two large ORFs are present in the same reading frame. They are most probably translated by readthrough of a UAG stop codon in the central part of the genome. The longest possible translation product (p125) has a predicted molecular mass of about 125 kDa. A significant homology can be found to the non-structural proteins of carmoviruses of the positive-strand RNA virus family Tombusviridae. These proteins also include the conserved RNA-dependent RNA polymerase (RDRP) domain. In contrast to the genome organization of these plant viruses, no ORF is present at the 3′ end of the
Using [3H]glucosamine and [3H]mannose labels, two virus-specific glycosylated polypeptide species with Mr values of about 200,000 (200K) and in the 75K to 100K range, respectively, were recognized in Berne virus-infected embryonic mule skin cells. In purified virions only the latter glycoprotein occurred. Concanavalin A was bound to the virion as evidenced by reduction in infectivity. Analyses using SDS-PAGE, blotting and glycoprotein identification with concanavalin A and horseradish peroxidase showed coincidence of the virion glycoprotein signals with the maximum infectivity and haemagglutinating activity in an isokinetic sucrose gradient. Polyclonal rabbit immune serum and a neutralizing and haemagglutination-inhibiting monoclonal antibody raised against Berne virus recognized both the 75K to 100K and the 200K glycoproteins. Using tunicamycin, a concentration-dependent inhibition of infectivity was noted; however, non-infectious particles containing the two major polypeptides (20K and 22K) were
Rapid RNA virus evolution is a major problem due to the devastating diseases caused by human, animal and plant-pathogenic RNA viruses. A previous genome-wide screen for host factors affecting recombination in Tomato bushy stunt tombusvirus (TBSV), a small monopartite plant virus, identified Xrn1p 5′-3′ exoribonuclease of yeast, a model host, whose absence led to increased appearance of recombinants [Serviene, E., Shapka, N., Cheng, C.P., Panavas, T., Phuangrat, B., Baker, J., Nagy, P.D., (2005). Genome-wide screen identifies host genes affecting viral RNA recombination. Proc. Natl. Acad. Sci. U. S. A. 102 (30), 10545-10550]. In this paper, we tested if over-expression of Xrn1p in yeast or expression of the analogous Xrn4p cytoplasmic 5′-3′ exoribonuclease, which has similar function in RNA degradation in Arabidopsis as Xrn1p in yeast, in Nicotiana benthamiana could affect the accumulation of tombusvirus RNA. We show that over-expression of Xrn1p led to almost complete degradation of TBSV ...
A significant number of RNA viruses assemble their protein containers and genomic material simultaneously. Here the implications of this protein-RNA co-assembly are investigated using an extended version of a model first proposed by Adam Zlotnick in 1994 (Zlotnick, 1994). The inspirations for this extended model are the cases of bacteriophage MS2 and the STMV virus, viruses that have been well characterised experimentally. Example pathways of RNA virus assembly have been enumerated and kinetic simulations have been run on these networks. The results show the most likely pathways of virus assembly and the concentrations of the intermediates. This work will also demonstrate how kinetic traps may be avoided when proteins are able to bind RNA during assembly. Additionally modelled are DNA cages, which are three-dimensional shapes made from double-helical DNA molecules. Such cages have been seen within viruses but may also be constructed artificially. This model has been used to produce energetically ...
Polivirüsün hücresel yaşam döngüsü (1) CD155 reseptörüne bağlanmasıyla başlar. Virüs endositozla alınır, ve viral RNA serbest kalır (2). Translation of the viral RNA occurs by an IRES-mediated mechanism (3). The polyprotein is cleaved, yielding mature viral proteins (4). The positive-sense RNA serves as template for complementary negative-strand synthesis, producing double-stranded replicative form (RF) RNA(5). Many positive strand RNA copies are produced from the single negative strand (6). The newly synthesized positive-sense RNA molecules can serve as templates for translation of more viral proteins (7) or can be enclosed in a capsid (8), which ultimately generates progeny virions. Lysis of the infected cell results in release of infectious progeny virions (9).[2] ...
Reverse transcriptases (RTs) polymerize DNA on RNA templates. They fall into several structurally related but distinct classes, and form an assemblage of RT-like enzymes which, in addition to RTs, also includes certain viral RNA-dependent RNA polymerases (RdRP) polymerizing RNA on RNA templates. It is generally believed that most RT-like enzymes originate from retrotransposons or viruses and have no specific function in the host cell, with telomerases being the only notable exception. Here we report on the discovery and properties of a novel class of RT-related cellular genes collectively named rvt. We present evidence that rvt are not components of retrotransposons or viruses, but single-copy genes with a characteristic domain structure, may contain introns in evolutionarily conserved positions, occur in syntenic regions, and evolve under purifying selection. These genes can be found in all major taxonomic groups including protists, fungi, animals, plants, and even bacteria, although they ...
in Gene (2004), 326. Some MX proteins are known to confer a specific resistance against a panel of single-stranded RNA viruses. Many diseases due to such viruses are known to affect cattle worldwide, raising the possibility ... [more ▼]. Some MX proteins are known to confer a specific resistance against a panel of single-stranded RNA viruses. Many diseases due to such viruses are known to affect cattle worldwide, raising the possibility that the identification of an antiviral isoform of a bovine MX protein would allow the implementation of genetic selection programs aimed at improving innate resistance of cattle. With this potential application in mind, the present study was designed to isolate the bovine Mx1 gene including its promoter region and to investigate its genomic organisation and promoter reactivity. The bovine Mx1 gene is made up of 15 exons. All exon-intron boundaries conformed to the consensus sequences. A PCR product that contained a approximately 1-kb, 5-flanking region ...
RNA enveloped viruses comprise several families belonging to plus and minus strand RNA viruses, such as retroviruses, flavoviruses and orthomyxoviruses. Viruses utilize cellular lipids during critical steps of replication like entry, assembly and egress. Growing evidence indicate important roles for lipids and lipid nanodomains in virus assembly. The proposed topic will cover key aspects of virus-membrane interactions during assembly and egress. A significant part of this special topic will address how enveloped viruses such as retroviruses, influenza, Ebola and Dengue viruses are able to recognize specific lipids in membrane during assembly and egress. Virus assembly and release involve specific and nonspecific interactions between viral proteins and membrane compartments. It is well established that assembly of retroviral Gag proteins occur predominantly on the PM. Membrane selection appears to be critical for productive virus production. Gaps in understanding of retroviral assembly still exist.
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There is no cure for this virus because RNA viruses arent diseases. They dont need a cure. They need cooperation.They are ribonucleic acid and a dynamic part of the genome. Our RNA is what allows us to evolve as a species. They are a natural part of our world and are microbes that have been…
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Benyviridae and Ophioviridae are both single-stranded RNA viruses that can infect plants and contain only one genus. Benyviridae, positive-sense RNA viruses with rod-shaped virions, can cause rhizomania, a disease in the roots of sugar beet. Some species of Ophioviridae are transmitted through soil and can infect many different plants including vegetables, trees and shrubs ...
Neurovirology is an interdisciplinary field representing a melding of virology, clinical neuroscience, molecular pathogenesis, diagnostic virology, molecular biology, and immunology. Neuroviral Infections: RNA Viruses and Retroviruses presents an…
genomes of accumulated deleterious changes (Muller, 1964) and to create or spread bene locial combinations of mutations in an efficient manner (Fisher, 1930;Muller, 1932), two processes which are not available to clonal organisms. Two distinct but not mutually exclusive types of genetic exchange operate in RNA viruses. The first, reassortment ...
genomes of accumulated deleterious changes (Muller, 1964) and to create or spread bene locial combinations of mutations in an efficient manner (Fisher, 1930;Muller, 1932), two processes which are not available to clonal organisms. Two distinct but not mutually exclusive types of genetic exchange operate in RNA viruses. The first, reassortment ...
This institute contributes to the education of students in Graduate School for Environmental and Life Science (Masters and Doctors Degree Course of Okayama University).
One fossil gene, called VP35, appeared in the same spot in the genomes of four different rodent species: two hamsters and two voles. This meant the material was likely acquired in or before the Miocene Epoch, prior to when these rodents evolved into distinct species some 16-23 million years ago.. In other words: It appears that the known filovirus family is at least as old as the common ancestor of hamsters and voles.. These rodents have billions of base pairs in their genomes, so the odds of a viral gene inserting itself at the same position in different species at different times are very small, Taylor says. Its likely that the insertion was present in the common ancestor of these rodents.. The genetic material in the VP35 fossil was more closely related to Ebola than to Marburg, indicating that the lines leading to these viruses had already begun diverging from each other in the Miocene.. The new study builds on Taylors previous work with Bruenn and other biologists, which used viral ...
Viruses are very small biological constructs which contain either DNA or RNA. As they lack cellular machinery and rely on an infected cell to actually replicate their viral genomes, there is debate as to whether viruses should be considered living. A virus consists of three main parts. 1) Genetic Material - This can be either DNA or RNA. Upon a viral infection, the virus inserts its genome into the host cell, where it is processed by various polymerases. 2) Protein capsid - this is a simple protein shell which envelops the genetic material and gives the virus structure. 3) Coat - there may exist certain proteins or lipids on the surface of the virus that identify the virus and aid in receptor binding to the cell surface. These surface modifications to the virus can induce an immune response in the host organism. The figure to the right is a schematic of a bacteriophage (virus that infects bacteria) inserting its DNA . Viral replication is essentially a positive feedback loop in which the ...
professor of biology at the University of Sydney, and his Australian colleagues decided to confront this mystery head on. Using viral genome data, they reconstructed the evolutionary history of 19 major virus families, each of which contained between 23 and 142 viruses found in diverse hosts ranging from mammals to fish to plants. They created phylogenetic, or evolutionary, trees for both the virus families and their host species and then compared them. They reasoned that if a virus had largely co-diverged with its host, evolving right alongside it, then the viruss phylogenetic tree should resemble its hosts: ancestral versions of the virus ought to have infected the hosts ancestors. But if the virus is jumping between species, the trees of the hosts and viruses will look different. How different depends on how many cross-species jumps are made ...
Viruses. Viruses and bacteria are too small to be seen without the aid of microscopes. As disease agents, their effects on mankind are well known. Both are ubiquitous and adaptable.. The Bridge Between Living and Non-Living. Someone once suggested that if people were the size of viruses, the entire population of the U.S. would fit on the end of two pencil erasers. There would be room left over for future generations. Extremely small, simple in structure, and widely distributed, viruses exist in a realm all their own. Viruses do not qualify as cells yet affect cells and so exist as if on a bridge between the living and nonliving.. Structure and Classification of Viruses. Viruses differ from cellular organisms in many ways. A virus contains only a single type of nucleic acid. This DNA or RNA may be single or double-stranded. The core of nucleic acid is covered by a protein coat called a capsid. Some of the proteins in the capsid are enzymes. A complete virus particle is called a virion. Some ...
So if viruses are not alive, what do they do and how do they do it? A virus, as long as it is not subjected to harsh conditions, is fairly stable. As it moves through the world, in saliva, on a counter top, or in a sneeze-induced projectile, it is waiting for its protein spikes to find the right cell. Once the virus finds a cell to which protein spikes can attach, it then migrates into the interior and takes over operations. Since a protein spike-cell wall match is necessary for the virus to enter, certain viruses can only infect certain cells. Once inside, the nucleic acid in the virus starts giving instructions to the cell, instructions which override those coming from the DNA in the nucleus of the cell. The virus then forces the cell to make copies of the virus, lots and lots of copies. After enough copies have been made, the virus moves on to other cells either by killing the host cell or diffusing back out through the cell wall ...
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A mathematical model that combines stochasticity and spatial structure describes the dynamics of the viral population during an infection cycle, and fitting the model to RNA and virus abundances over time shows that poliovirus follows a geometric replication mode.
Geoff Kuenning, a professor of computer science at Harvey Mudd College, provides this explanation. Malicious software comes in several flavors, distinguished primarily by their method of propagation. The two most pervasive forms are viruses and worms. A virus attaches itself to an existing program such that, when that program is executed, bad things happen. Like a biological virus, it cannot live without a host. In contrast, a worm is an independent program that reproduces itself without requiring a host program. Depending on the form, a worm may be able to propagate without any action on the victims part. Most malicious software today consists of worms rather than viruses. Worms and viruses require slightly different protection mechanisms because of their different propagation methods. A virus scanner operates by searching for the signatures of known viruses. A signature is a characteristic pattern that occurs in every copy of a virus. It might be a string of characters, such as a message that ...
See on - Virology News Viruses have generally been studied either as disease-causing infectious agents that have a negative impact on the host (most eukaryote-infecting viruses), or as tools for molecular biology (especially bacteria-infecting viruses, or phage). Virus ecology looks at the more complex issues of virus-host-environment interactions. For plant viruses this includes studies…
Lets face it: the last thing your computer needs is a virus. Viruses are nasty programs designed to damage computers and networks. A virus may cause odd messages to appear on screens, spread itself by sending unintended emails to your email contacts, damage your data, or worse. Whatever the case, a virus is never a welcome surprise. The Internet is a particularly dangerous tool for those who create viruses, as it provides them with access to so many computers, opening a whole new world of trouble. Most viruses spread when users share infected floppy discs, unknowingly run infected programs or open email attachments. If you download software (or just open attachments from friends, relatives, or business associates), theres a chance youll bring home one of these digital bugs. Still, its fairly easy to protect your computer and valuable info from viruses. Youll just need to consistently do a couple of things:. 1) Never open, view or run an unexpected email attachment, even if its from someone ...
It is January 21st, 2021. Its always sad and frustrating when I read an article that includes misinformation about the Wuhan virus. A trip to the CDCs website will give you the actual numbers, but its probable that the CDC hadnt changed their numbers to reflect reality at the time of this article. As of today, in the United States, 18,700 persons have died from the virus, the vast majority of whom were elderly. The leftist media currently exclaims that over 300,000 have died of the virus, but that is misleading. Just testing positive for the virus at the time of death will earn the deceased the medical code of a Covid-19 death, but there is a difference between dying FROM the virus and dying having tested positive for the virus. Only 6% of the deaths that the leftist media state have been solely from the virus. 6% is 18,700. The rest, most of whom were elderly, had an average of 2.9 co-morbidities and primarily died of an heart attack, suicide, diabetes complications, etc. and averaged ...
It is January 21st, 2021. Its always sad and frustrating when I read an article that includes misinformation about the Wuhan virus. A trip to the CDCs website will give you the actual numbers, but its probable that the CDC hadnt changed their numbers to reflect reality at the time of this article. As of today, in the United States, 18,700 persons have died from the virus, the vast majority of whom were elderly. The leftist media currently exclaims that over 300,000 have died of the virus, but that is misleading. Just testing positive for the virus at the time of death will earn the deceased the medical code of a Covid-19 death, but there is a difference between dying FROM the virus and dying having tested positive for the virus. Only 6% of the deaths that the leftist media state have been solely from the virus. 6% is 18,700. The rest, most of whom were elderly, had an average of 2.9 co-morbidities and primarily died of an heart attack, suicide, diabetes complications, etc. and averaged ...
The W32.Shodi.C program is a virus that pretends to be executable or .exe files. It can also drop a fixed access tool. When a file contaminated w/ a W32.Shodi.C virus is opened, it extracts the original file to a file with a .sho extension, and then it opens it. For instance, if notepad.exe is contaminated, the W32.Shodi.C program will extract the notepad program to notepad.sho and then opens it. The virus searches for the files with .exe extensions on all the hard drives, beginning w/ drive C. The virus looks for the folders on the hard drive, except names such as windows, system, and system32. The virus doesnt contaminate the files with names such as iexplorer.exe, ccApp.exe, and ccRegVfy.exe. The virus conceals itself to some of the files that it locates. The W32.Shodi.Cprogram changes its icon to resemble that of the host file. The virus creates a temporary duplicate of itself as %System%Shohdi.hdi ...
Mouse K virus was first discovered by Lawrence Kilham - thus K virus. It belongs to the family Pavovaviridae. The virus is usually spread by the oronasal route. When a young mouse is orally inoculated with the virus, the virus first replicates in the intestine and then spreads to other organs such as liver, lung, spleen and brain. Older mice may mount an immune response to the virus and thus may limit the spread of the virus through the body. However, athymic or nude mice suffer significantly if infected ...
Instead, the researchers focused on glycoproteins, which sit on the outside of all viruses and attach to cells in the body, allowing the viruses to do their dirty work by infecting cells and making us sick. Using that knowledge, the researchers created a macromolecule, which is basically one giant molecule made of smaller subunits. This macromolecule has key factors that are crucial in fighting viruses. First, its able to attract viruses towards itself using electrostatic charges. Once the virus is close, the macromolecule attaches to the virus and makes the virus unable to attach to healthy cells. Then it neutralizes the virus acidity levels, which makes it less able to replicate. ...
Publikations-Datenbank der Fraunhofer Wissenschaftler und Institute: Aufsätze, Studien, Forschungsberichte, Konferenzbeiträge, Tagungsbände, Patente und Gebrauchsmuster
Survey of Microorganisms. Virus Bacteria Cyanobacteria Algae Fungi protozoa. VIRUS. Obligated intracellular parasite. host specific: bacteriophage animal virus plant virus according to its genetic material DNA virus RNA virus Shape: Slideshow 202506 by Faraday
Emerging human and zoonotic RNA viruses including SARS-CoV cause significant global morbidity, mortality, and social disruption. The current model for RNA virus...
Principal Investigator:ENAMI Masayoshi, Project Period (FY):1997 - 1999, Research Category:Grant-in-Aid for Scientific Research (A), Section:展開研究, Research Field:Virology
Watch video lessons, and learn about the different aspects of various viral infections, like the stomach flu, HIV and rabies. Take the quizzes that...
Medical Xpress is a web-based medical and health news service that features the most comprehensive coverage in the fields of neuroscience, cardiology, cancer, HIV/AIDS, psychology, psychiatry, dentistry, genetics, diseases and conditions, medications and more.
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Vivaldi Biosciences was developing small molecule antiviral drugs for the treatment of respiratory diseases caused by negative-strand RNA viruses, including
See the latest information on computer virus attacks and their removal. McAfee is the leader in internet security and virus detection. Keep up to date on the most recent virus threats, recently discovered viruses and recently updated viruses.
Virus-like RNA-based origin[edit]. Sex might also have been present even earlier, in the hypothesized RNA world that preceded ... such as influenza virus, and in extant double-stranded segmented RNA viruses such as reovirus.[64] ... the VE hypothesis specifies a pox-like virus as the lysogenic virus. A pox-like virus is a likely ancestor because of its ... RNA world was based on the type of sexual interaction that is known to occur in extant single-stranded segmented RNA viruses, ...
MC is caused by a poxvirus called the molluscum contagiosum virus (MCV).[1] The virus is spread either by direct contact ... Molluscum contagiosum virus spread by direct contact or contaminated objects[4]. Risk factors. Weak immune system, atopic ... Chen, X; Anstey, AV; Bugert, JJ (October 2013). "Molluscum contagiosum virus infection". Lancet Infectious Diseases. 13 (10): ... "Treatment Options - Molluscum Contagiosum - Pox viruses - CDC". 2 October 2017.. ...
This is to keep the virus in circulation thereby exposing the population to the virus at an early age, when it is less harmful ... After a chickenpox infection, the virus remains dormant in the body's nerve tissues. The immune system keeps the virus at bay, ... "Understanding Viruses (2nd ed.). Jones & Bartlett. p. 459. ISBN 978-0-7637-8553-6. . Archived from the original on 1 October ... Wharton M (1996). "The epidemiology of varicella-zoster virus infections". Infect Dis Clin North Am. 10 (3): 571-81. doi: ...
Infection with this virus is thought to be lifelong, but a healthy immune system will keep the virus in check. Many people ... PAN, polyadenylated nuclear RNA - non-coding linear and circular RNAs miRNAs (mirKs) - viral microRNAs expressed during latency ... When the virus enters into lytic replication, thousands of virus particles can be made from a single cell, which usually ... When the virus reactivates into lytic replication, it is believed that the virus genome is replicated as a continuous linear ...
The virus attacks compromised skin through direct contact, possibly entering through tiny cuts and abrasions in the stratum ... is a new wart treatment which may trigger a host immune response to the wart virus, resulting in wart resolution. It is now ... RNA virus. Paramyxoviridae. *MeV *Measles. Togaviridae. *Rubella virus *Rubella. *Congenital rubella syndrome ("German measles ...
... is a skin infection primarily caused by the herpes simplex virus. The virus infects the cells in the ... Infection with either type of the HSV viruses occurs in the following way: First, the virus comes in contact with damaged skin ... The virus moves to the nerve cells from where it can reactivate. Once the condition has recurred, it is normally a mild ... This type of virus may be transmitted even if the symptoms are not yet present. Some individuals can have very mild symptoms ...
DNA virus. HBV (B). RNA virus. CBV. HAV (A). HCV (C). HDV (D). HEV (E). HGV (G). ... DNA virus. Human polyomavirus 2 Progressive multifocal leukoencephalopathy. RNA virus. MeV Subacute sclerosing panencephalitis ... RNA virus. HCV Hepatocellular carcinoma. Splenic marginal zone lymphoma. HTLV-I Adult T-cell leukemia/lymphoma. ... DNA virus. HBV Hepatocellular carcinoma. HPV Cervical cancer. Anal cancer. Penile cancer. Vulvar cancer. Vaginal cancer. ...
Usually, herpangina is produced by one particular strain of coxsackie virus A (and the term "herpangina virus" refers to ... RNA virus. Paramyxoviridae. *MeV *Measles. Togaviridae. *Rubella virus *Rubella. *Congenital rubella syndrome ("German measles ...
... s are caused by the human papilloma virus (HPV). There are about 130 known types of human papilloma viruses.[8] HPV infects ... Warts are caused by a virus, and toads do not harbor it.[42] A variety of traditional folk remedies and rituals claim to be ... The virus is resistant to drying and heat, but killed by 100 °C (212 °F) and ultraviolet radiation.[16] ... The virus is relatively hardy and immune to many common disinfectants. Exposure to 90% ethanol for at least 1 minute, 2% ...
The virus moves from the mouth to remain latent in the central nervous system. In approximately one-third of people, the virus ... Despite no cure or vaccine for the virus, a human body's immune system and specialty antigens typically fight the virus.[16] ... The cause is usually herpes simplex virus type 1 (HSV-1) and occasionally herpes simplex virus type 2 (HSV-2).[1] The infection ... but the virus remains dormant in the facial nerve.[1] The virus may periodically reactivate to create another outbreak of sores ...
... is an infectious disease caused by certain types of virus.[2] Most infections occur before the age of three.[1] ... The disease was first described in 1910 while the causal virus was determined in 1988.[1] The disease may reactivate in those ... RNA virus. Paramyxoviridae. *MeV *Measles. Togaviridae. *Rubella virus *Rubella. *Congenital rubella syndrome ("German measles ... "Contributions of neurotropic human herpesviruses herpes simplex virus 1 and human herpesvirus 6 to neurodegenerative disease ...
Replication follows the double-stranded RNA virus replication model. Double-stranded RNA virus transcription is the method of ... Dolja, Valerian V (2001). "Capsid-Less RNA Viruses". eLS. doi:10.1002/9780470015902.a0023269. ISBN 978-0470016176. ICTVdB ... often are classified as dsDNA viruses, in contrast to the official ssRNA(+) ICTV classification). The virus exits the host cell ... Endornaviridae is a family of viruses. Plants, fungi, and oomycetes serve as natural hosts. There are currently 31 species in ...
Replication follows the positive-strand RNA virus replication model. Positive-strand RNA virus transcription is the method of ... Narnaviridae Narnavirus Saccharomyces 20S RNA narnavirus Saccharomyces 23S RNA narnavirus ICTV. "Virus Taxonomy: 2014 Release ... Narnavirus is a genus of positive-strand RNA viruses, in the family Narnaviridae. Fungi serve as natural hosts. There are ... The genome has one open reading frame which encodes the RNA-dependent RNA polymerase (RdRp). The genome is associated with the ...
Plant viruses induce the rearrangement of membranes structures to form the viroplasm. This is mostly shown for plant RNA ... Viroplasms have been found in the cauliflower mosaic virus, rotavirus, vaccinia virus and the rice dwarf virus. These appear ... The number and the size of viroplasms depend on the virus, the virus isolate, hosts species, and the stage of the infection. ... The viroplasm could also prevent virus degradation by proteases and nucleases. In the case of the Cauliflower mosaic virus ( ...
"Subversion of cellular autophagosomal machinery by RNA viruses". PLoS Biol. 3 (5): e156. doi:10.1371/journal.pbio.0030156. PMC ... Vesicular stomatitis virus is believed to be taken up by the autophagosome from the cytosol and translocated to the endosomes ... A subset of viruses and bacteria subvert the autophagic pathway to promote their own replication.[63] Galectin-8 has recently ... where detection takes place by a member of the PRRs called toll-like receptor 7, detecting single stranded RNA. Following ...
Both DNA and RNA viruses can undergo recombination. When two or more viruses, each containing lethal genomic damage infect the ... adenovirus simian virus 40, vaccinia virus, reovirus, poliovirus and herpes simplex virus as well as numerous bacteriophages.[ ... Viruses[edit]. Viruses are capsid-encoding organisms composed of proteins and nucleic acids that can self-assemble after ... Many types of virus are capable of genetic recombination. When two or more individual viruses of the same type infect a cell, ...
Loeb L A, Harris C C Cancer Res 2008;68:6863-6872 "DNA and RNA Tumor Viruses." DNA and RNA Tumor Viruses. N.p., n.d. Web. 11 ... some virus are co-carcinogens like Herpesviruses, Epstein-Barr virus (EBV) and human herpesvirus 4 (HHV-4) Over intake beta ...
Attenuated RNA virus vaccines can revert to virulent forms. RNA viruses released in nature for pest control purposes can mutate ... Collective behavior of viruses was documented with mutant RNA viruses resistant to nucleotide analogues. The study of this ... and is comparable to values calculated for other RNA viruses. High mutation rates and quasispecies were verified for other RNA ... In RNA virus genetics when we speak of "a mutant" the entity we handle is a cloud of mutants in which the specific mutation to ...
In particular, reassortment occurs among influenza viruses, whose genomes consist of eight distinct segments of RNA. These ... flu strains were caused by reassortment between an avian virus and a human virus. In addition, the H1N1 virus responsible for ... Simon-Loriere, Etienne; Holmes, Edward C. (2011). "Why do RNA viruses recombine?". Nature Reviews Microbiology. 9 (8): 617-626 ... Studies on host-virus interactions in the chick embryo-influenza virus system. VI. Evidence for multiplicity reactivation of ...
Renault, Sylvaine (2012). "RNA Viruses in Parasitoid Wasps". Parasitoid Viruses Symbionts and Pathogens. Pivnick, Kenneth ( ... They have been shown to carry Rioviridae RNA viruses, one of only a few parasitoids to carry them. Quicke, Donald (22 December ... Beckage, Nancy (2011). Parasitoid Viruses: Symbionts and Pathogens. p. 194. v t e. ...
Viruses that use RNA as their genetic material have rapid mutation rates, which can be an advantage since these viruses will ... Without proofreading error rates are a thousandfold higher; because many viruses rely on DNA and RNA polymerases that lack ... "Mutation rates among RNA viruses". Proc. Natl. Acad. Sci. U.S.A. 96 (24): 13910-3. Bibcode:1999PNAS...9613910D. doi:10.1073/ ... Viruses can also carry DNA between organisms, allowing transfer of genes even across biological domains. Large-scale gene ...
"DNA and RNA tumor viruses". The Lasker Foundation. Retrieved 30 December 2017. Roberts, Sam (5 March 2016). "Dr. Myron G. ... particularly of the tobacco mosaic virus; Fellow of the American Academy of Arts and Sciences and of the Biophysical Society ( ... known for his work in Tobacco mosaic virus; first president of the Biophysical Society; member of the National Academy of ... arbovirologist who discovered hundreds of viruses and advised on emerging infectious diseases Theobald Smith (B.Phil. 1881) - ...
... double-stranded RNA of viruses; or the unmethylated CpG islands of bacterial and viral DNA; and also of the CpG islands found ... TLR7 messenger RNA expression levels in dairy animals in a natural outbreak of foot-and-mouth disease have been reported. When ... Its ligand is retroviral double-stranded RNA (dsRNA), which activates the TRIF dependent signalling pathway. To explore the ... February 2011). "A novel Toll-like receptor that recognizes vesicular stomatitis virus". The Journal of Biological Chemistry. ...
... double-stranded RNA viruses; (IV) positive-sense single-stranded RNA viruses; (V) negative-sense single-stranded RNA viruses; ( ... Sokuluk virus, Yokose virus, Dakar bat virus, Bukalasa bat virus, Carey Island virus, Phnom Penh bat virus, Rio Bravo bat virus ... These zoonotic viruses include the rabies virus, SARS-CoV, MERS-CoV, Marburg virus, Nipah virus, and Hendra virus. While ... Most of the viruses harbored by bats are RNA viruses, though they are also known to have DNA viruses. Bats are more tolerant of ...
Most plant viruses have small, single-stranded RNA genomes. However some plant viruses also have double stranded RNA or single ... the insect and virus are specific for virus transmission such as the beet leafhopper that transmits the curly top virus causing ... Dodder, for example, is used as a conduit either for the transmission of viruses or virus-like agents from a host plant to a ... Plant viruses can have several more proteins and employ many different molecular translation methods. Plant viruses are ...
RNA virus recombinationEdit. Numerous RNA viruses are capable of genetic recombination when at least two viral genomes are ... Mechanism of RNA recombination in carmo- and tombusviruses: evidence for template switching by the RNA-dependent RNA polymerase ... influenza virus)[19] and coronaviridae ((+)ssRNA) (e.g. SARS).[20] Recombination in RNA viruses appears to be an adaptation for ... a b Barr JN, Fearns R. How RNA viruses maintain their genome integrity. J Gen Virol. 2010 Jun;91(Pt 6):1373-87. doi: 10.1099/ ...
Viruses have enormous populations, are doubtfully living since they consist of little more than a string of DNA or RNA in a ... "Experimental evolution of plant RNA viruses". Heredity. 100 (5): 478-483. doi:10.1038/sj.hdy.6801088. PMC 7094686. PMID ... All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the ... Viruses are a special case, driven by a balance of mutation and selection, and can be treated as quasispecies. Biologists and ...
Since the genetic material in the virus consists of RNA the coat protein contains RNA binding sites. Additionally, the coat ... Bink HH, Pleij CW (2002). "RNA-protein interactions in spherical viruses". Arch Virol. 147 (12): 2261-79. doi:10.1007/s00705- ... The virus coat is composed of 180 copies of the coat protein arranged in an icosahedral shell. Fundamentally, the viral coat ... Canady MA, Larson SB, Day J, McPherson A (1996). "Crystal structure of turnip yellow mosaic virus". Nat Struct Biol. 3 (9): 771 ...
Floyd R.A.; Schneider J.E.; Dittmer D.P. (March 2004). "Methylene blue photoinactivation of RNA viruses". Antiviral Res. 61 (3 ... Since it is a temporary staining technique, methylene blue can also be used to examine RNA or DNA under the microscope or in a ... It has been studied in AIDS-related Kaposi's sarcoma, West Nile virus, and to inactivate staphylococcus aureus, and HIV-1. ... Papin J.F.; Floyd R.A.; Dittmer D.P. (November 2005). "Methylene blue photoinactivation abolishes West Nile virus infectivity ...
As in B1MaV this virus has three segmented negative RNA strands within its genome. Citrus psorosis virus also has three ... This virus often occurs along with lettuce big-vein virus. Lettuce big-vein virus causes the veins of the plant to be banded ... "Aspiviridae - Aspiviridae - Negative-sense RNA Viruses". International Committee on Taxonomy of Viruses (ICTV). Retrieved 2019- ... RNA-dependent RNA polymerase) replicase. The presence of these two ORFs in the largest RNA strand and the two ORF's having the ...
Virus Taxonomy-Sixth Report of the International Committee on Taxonomy of Viruses. Archives of Virology Supplement. 10. Vienna ... et sua genoma per RNA unius fili sensu negativo scribunt. Duo notissima familiae genera sunt Ebolavirus et Marburgvirus. Ambo ... Virus Taxonomy-Seventh Report of the International Committee on Taxonomy of Viruses. San Diego, USA: Academic Press. pp. 539-48 ... Virus Taxonomy-Eighth Report of the International Committee on Taxonomy of Viruses. San Diego, USA: Elsevier/Academic Press. pp ...
Spissistilus festinus virus 1"[39]. Einzelstrang-RNA-Viren mit negativer Polarität (ss(−)RNA: negative single-stranded RNA)[ ... Usutu-Virus - en. Usutu virus (USUV), Zika-Virus - en. Zika virus (ZIKV), sowie Gelbfieber-Virus - en. Yellow fever virus (YFV) ... Genus ‚Negevirus', mit Species ‚Blackford virus', ‚Bofa virus', ‚Buckhurst virus', ‚Marsac virus', sowie ‚Muthill virus'[53] ... Sorghum mosaic virus (SrMV), Lily-Mottle-Virus - en. Lily mottle virus (LMoV), sowie Sellerie-Virus Y - en. Apium virus Y (ApVY ...
1987). "Molecular cloning and sequencing of a human hepatitis delta (delta) virus RNA". Nature. 329 (6137): 343-346. doi: ... Glej glavni članek Virus hepatitisa D. Povzročitelj virus hepatitisa D je majhen krožen virus RNK z ovojnico. Spada med. t. i. ... Hepatitis D je oblika hepatitisa, ki ga povzroča virus hepatitisa D (VHD); le-ta za svoj razvoj potrebuje virus hepatitisa B. ... 5,0 5,1 5,2 5,3 Štunf Š., Seme K., Poljak M.: Virus hepatitisa D. Medicinski razgledi 2005; 44: 463-471. ...
... detecting its RNA or proteins, or detecting antibodies against the virus in a person's blood.[98] Isolating the virus by cell ... The four are Bundibugyo virus (BDBV), Sudan virus (SUDV), Taï Forest virus (TAFV) and one simply called Ebola virus (EBOV, ... The virus responsible for the initial outbreak, first thought to be Marburg virus, was later identified as a new type of virus ... Main articles: Ebola virus cases in the United States, Ebola virus disease in Spain, and Ebola virus disease in the United ...
Replication follows the positive stranded RNA virus replication model. Positive stranded rna virus transcription is the method ... The virus exits the host cell by bacteria lysis. Enterobacteria serve as the natural host. "Viral Zone". ExPASy. Retrieved 15 ... Allolevivirus is a genus of viruses, in the family Leviviridae. Enterobacteria serve as natural hosts. There are currently only ... "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015. Viralzone: Allolevivirus ICTV. ...
1993). "On the evolution of RNA editing". Trends in Genetics. 9 (8): 265-268. doi:10.1016/0168-9525(93)90011-6.. ... Daniel, Chammiran; Behm, Mikaela; Öhman, Marie (2015). "The role of Alu elements in the cis-regulation of RNA processing". ... RNA editing may have arisen in Trypanosoma brucei.[21][24][23][25][26] ...
Confirmation is by laboratory testing to detect the virus's RNA, antibodies for the virus, or the virus itself in cell culture. ... Lujo virus. References[edit]. *^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad "Lassa fever". WHO. March 2016 ... The Lassa virus is one of several viruses identified by WHO as a likely cause of a future epidemic. They therefore list it for ... Lassa virus is a member of the Arenavirida family of viruses.[7] Specifically it is an old world arenavirus, which is enveloped ...
... is caused by yellow fever virus, a 40- to 50-nm-wide enveloped RNA virus, the type species and namesake of the ... Other viral hemorrhagic fevers, such as Ebola virus, Lassa virus, Marburg virus, and Junin virus, must be excluded as the cause ... The virus is an RNA virus of the genus Flavivirus.[7] The disease may be difficult to tell apart from other illnesses, ... "An RNA Pseudoknot Is Required for Production of Yellow Fever Virus Subgenomic RNA by the Host Nuclease XRN1". Journal of ...
Virus RNA polymerases use VPg as primer. VPg as primer uses both minus and plus strand RNA synthesis. Picornavirus replication ... deformed wing virus, acute bee paralysis virus, Drosophila C virus, Rhopalosiphum padi virus, and Himetobi P virus. Several ... This family includes Infectious flacherie virus and SeIV-1 virus. Another virus is Nora virus from Drosophila melanogaster. ... strand RNA genome is replicated through a double-stranded RNA intermediate that is formed using viral RDRP (RNA-Dependent RNA ...
... the latter virus has the largest currently reported ssDNA genome. Defenses against these viruses may involve RNA interference ... Archaea can be infected by double-stranded DNA viruses that are unrelated to any other form of virus and have a variety of ... Archaea were split off as a third domain because of the large differences in their ribosomal RNA structure. The particular RNA ... although there are many introns in their transfer RNA and ribosomal RNA genes,[146] and introns may occur in a few protein- ...
... the TATA box is found at RNA polymerase II promoter regions, although some in vitro studies have demonstrated that RNA ... MicroRNAs also play a role in replicating viruses such as HIV-1.[44] Novel HIV-1-encoded microRNA have been found to enhance ... "RNA polymerase III accurately initiates transcription from RNA polymerase II promoters in vitro". The Journal of Biological ... TATA-binding protein (TBP) can be recruited in two ways, by SAGA, a cofactor for RNA polymerase II, or by TFIID.[11] When ...
Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription is the method ... Newbury-1 virus Genus Norovirus; type species: Norwalk virus Genus Sapovirus; type species: Sapporo virus Genus Vesivirus; type ... Norwalk virus Genus: Sapovirus Sapporo virus Genus: Vesivirus Feline calicivirus Vesicular exanthema of swine virus Two ... All viruses in this family possess a non-segmented, polyadenylated, positive sense single stand RNA genome of ~7.5-8.5 ...
These viruses infect fish and other aquatic animals. The reconstruction has high enough resolution to have amino acid side ... Important information on protein synthesis, ligand binding and RNA interaction can be obtained using this novel technique at ... Methods are also available for making 3D reconstructions of helical samples (such as tobacco mosaic virus), taking advantage of ... "3.3 A cryo-EM structure of a nonenveloped virus reveals a priming mechanism for cell entry". Cell. 141 (3): 472-82. doi:10.1016 ...
RNA interference (RNAi) and small-RNA biology; DNA replication; RNA splicing; signal transduction; genome structure; non-coding ... Upon taking charge in 1968, he focused the Laboratory on cancer research, creating a tumor virus group and successfully ... Adrian Krainer, studies RNA splicing and developed nusinersen for treatment of spinal muscular atrophy (SMA). ... Gregory Hannon (currently at CRUK Cambridge Institute), research on RNA interference, Member of the National Academy of ...
Michels AA, Nguyen VT, Fraldi A, Labas V, Edwards M, Bonnet F, Lania L, Bensaude O (2003). "MAQ1 and 7SK RNA interact with CDK9 ... and act as a negative regulator of human immunodeficiency virus type 1 (HIV-1) Tat protein. Two alternatively spliced ... Nguyen VT, Kiss T, Michels AA, Bensaude O (2001). "7SK small nuclear RNA binds to and inhibits the activity of CDK9/cyclin T ... "Analysis of the effect of natural sequence variation in Tat and in cyclin T on the formation and RNA binding properties of Tat- ...
... activation with cellular viremia and plasma HIV RNA levels in asymptomatic patients infected by human immunodeficiency virus ...
DNA virus. HBV (B). RNA virus. CBV. HAV (A). HCV (C). HDV (D). HEV (E). HGV (G). ... DNA virus. JCV Progressive multifocal leukoencephalopathy. RNA virus. MeV Subacute sclerosing panencephalitis. LCV Lymphocytic ... RNA virus. HCV Hepatocellular carcinoma. Splenic marginal zone lymphoma. HTLV-I Adult T-cell leukemia/lymphoma. ... The JC virus or John Cunningham virus is a type of human polyomavirus (formerly known as papovavirus). It was identified by ...
"for their discovery of catalytic properties of RNA"[۳۳] ۱۹۹۲ رادولف مارکوس[۱] United States "for his contributions to the ... "for their discoveries concerning the interaction between tumour viruses and the genetic material of the cell"[۶۱] ... "for his discovery of آران‌ای سرکوبگر - gene silencing by double-stranded RNA"[۷۹] ... "for their discoveries concerning genetic control of enzyme and virus synthesis"[۵۵] ...
Virus. References[change , change source]. *↑ 1.0 1.1 Whitman W, Coleman D, Wiebe W (1998). "Prokaryotes: the unseen majority" ... All modern ideas start with the sequence analysis of DNA and RNA. In 1987, Carl Woese, the forerunner of the molecular ... Bacteria vary widely in size and shape, but in general they are at least ten times larger than viruses. A typical bacterium is ... phylogeny revolution, divided bacteria into 11 divisions based on 16S ribosomal RNA (SSU) sequences:[5][6] ...
The genome of SVNV is a negative sense single stranded RNA virus (Group V) that has three segments (S, M, and L segments). The ... Soybean vein necrosis virus (SVNV, previously: Soybean vein necrosis associated virus SVNaV) is a plant pathogenic virus of ... Portions of the virus that are believed to be critical for the spread of this virus, based on what is known for other members ... Like other members of Bunyavirales, this virus is enveloped and has a negative sense single-stranded RNA (−ssRNA) genome ...
RNA virus. *Robert Frost. *Ron Tandberg. *Rose. *Lionel Rose. *Rotifer. *Royal Institution ...
... herpes simplex virus 1 (HSV-1) - herpes simplex virus 2 (HSV-2) - herpes varicella zoster virus (VZV) - herpes viruses - highly ... RNA) - ribosome - RNA - route of administration - RT-PCR - RTI - Ryan White C.A.R.E. act ... human papilloma virus (HPV) - human T cell lymphotropic virus type I (HTLV-I) - human T cell lymphotropic virus type II (HTLV- ... human immunodeficiency virus type 1 (HIV-1) - human immunodeficiency virus type 2 (HIV-2) - human leukocyte antigens (HLA) - ...
RNA binding. • protein heterodimerization activity. • nucleic acid binding. • protein kinase binding. • core promoter binding. ... 1991). «Specific complex of human immunodeficiency virus type 1 rev and nucleolar B23 proteins: dissociation by the Rev ... RNA polymerase II transcription coactivator activity. • transcription factor binding. • activating transcription factor binding ... regulation of transcription from RNA polymerase II promoter. • cellular response to UV. • ribosomal large subunit export from ...
... crosslinks in virus DNA also appear to be removed by a recombinational repair process as occurs in SV40 virus infected ... Research on psoralen has historically focused on interactions with DNA and RNA (in particular, ICL formation). Psoralen, ... and therefore have been used extensively for the analysis of interactions and structures for both DNA and RNA.[26][27] ... "Repair of psoralen-treated DNA by genetic recombination in human cells infected with herpes simplex virus". Cancer Res. 41 (12 ...
Land A, Braakman I (August 2001). "Folding of the human immunodeficiency virus type 1 envelope glycoprotein in the endoplasmic ... and use of endonuclease digestion of PCR-amplified RNA to demonstrate lack of mRNA expression from the second allele". American ... Dedera DA, Gu RL, Ratner L (March 1992). "Role of asparagine-linked glycosylation in human immunodeficiency virus type 1 ... "Effect of a glucosidase inhibitor on the bioactivity and immunoreactivity of human immunodeficiency virus type 1 envelope ...
Such viruses are either single stranded RNA (e.g. HIV) or double stranded DNA (e.g. Hepatitis B virus) viruses. ... RNA: consists of a dimer RNA. It has a cap at the 5' end and a poly(A) tail at the 3' end. The RNA genome also has terminal ... In most viruses, DNA is transcribed into RNA, and then RNA is translated into protein. However, retroviruses function ... Group VI viruses[edit]. All members of Group VI use virally encoded reverse transcriptase, an RNA-dependent DNA polymerase, to ...
As arqueas poden ser infectadas por virus de ADN bicatenario que non están relacionados con ningún outro tipo de virus e teñen ... Werner F (2007). "Structure and function of archaeal RNA polymerases". Mol. Microbiol. 65 (6): 1395-404. PMID 17697097. doi: ... Pietilä MK, Roine E, Paulin L, Kalkkinen N, Bamford DH (2009). "An ssDNA virus infecting archaea; A new lineage of viruses with ... Ligamenvirales, virus que infectan arqueas. Ligazóns externas[editar , editar a fonte]. *. "Introduction to the Archaea". UCMP ...
Domingo, Esteban (2001). "RNA Virus Genomes". ELS. doi:10.1002/9780470015902.a0001488.pub2. ISBN 0470016175. ... ೪೧.೦ ೪೧.೧ Eddy SR (December 2001). "Non-coding RNA genes and the modern RNA world". Nat. Rev. Genet. 2 (12): 919-29. doi: ... Koonin, Eugene V.; Dolja, Valerian V.; Morris, T. Jack (January 1993). "Evolution and Taxonomy of Positive-Strand RNA Viruses: ... "Basic concepts in RNA virus evolution.". FASEB Journal 10 (8): 859-64. PMID 8666162. ...
Measles (rubeola) is an infectious disease caused by multiplication of a single-strand ribonucleic acid (RNA) virus of the ...
Functional conservation despite structural divergence in ligand-responsive RNA switches Mark A. Boerneke, Sergey M. Dibrov, ...
Large-scale discovery of vertebrate RNA viruses shows that, although viruses often jump between hosts, most have co-evolved ... Large-scale discovery of vertebrate RNA viruses shows that, although viruses often jump between hosts, most have co-evolved ... Large-scale discovery of vertebrate RNA viruses shows that, although viruses often jump between hosts, most have co-evolved ... with their hosts over millions of years The evolutionary history of viruses is largely unknown. ...
Riboviruses (RNA viruses exclusive of retroviruses) tend to display very high mutation rates (4); however, quantifying those ... Mutation rates among RNA viruses. John W. Drake and John J. Holland ... Bacteriophage φ6 has a segmented, double-stranded RNA genome and thus differs profoundly from the viruses in Table 1. ... A previous analysis of mutation rates in RNA viruses (specifically in riboviruses rather than retroviruses) was constrained by ...
... Version 05 February 2006 (temporary). ... Double-stranded RNA Viruses Click on an image to view larger version & data in a new window ... other Viruses. * Double-stranded RNA Viruses * Single-stranded Negative Sense RNA Viruses ... Double-stranded RNA Viruses Branch Page. collections. * Double-stranded RNA Viruses Images ...
... Click on an image to view larger version & data in a new window ... Arenaviridae are RNA viruses whose particles are spherical and have an average diameter of 110-130 nanometers. Arenaviridae ... Version 05 February 2006 (temporary). in The Tree ... other Viruses. * Double-stranded RNA Viruses * Single-stranded Negative Sense RNA Viruses ...
RNA-virus har små og tette genom.[1] RNA-virus benytter RNA-avhengig RNA-polymerase eller revers transkriptase til å kopiere ... RNA-virus er virus som benytter RNA som arvestoff.[1] De benytter organismer fra alle de biologiske rikene som verter.[2] RNA- ... De enkelttråda RNA-virusene kan ha både positiv og negativ RNA-polaritet.[3] RNA-virus er den vanligste klassen av virus som ... og mutasjoner i genoma til RNA-virus blir slik lettere videreførte. Dette bevirker at RNA-virus utvikler seg mye hurtigere enn ...
Among the diverse strategies used by viruses to induce human disease, their ability to cause immune defects has received ... Gazzolo L., Dodon M.D., Gessain A., Robert-Guroff M., de-The G. (1985) RNA Viruses and Lymphocyte Immune Functions. In: Gallo R ... Hardy, W.D., Jr., (1984) In Human T-cell leukemia/lymphoma virus, eds. Gallo, R.C., Essex, M.E. & Gross, L. (Cold Spring Harbor ... Among the diverse strategies used by viruses to induce human disease, their ability to cause immune defects has received ...
Single-stranded Positive Sense RNA Viruses articles & notes. *Single-stranded Positive Sense RNA Viruses Branch Page ... Single-stranded Positive Sense RNA Viruses Images Click on an image to view larger version & data in a new window ... other Viruses. * Double-stranded RNA Viruses * Single-stranded Negative Sense RNA Viruses ... Single-stranded Positive Sense RNA Viruses Movies people. * Single-stranded Positive Sense RNA Viruses People ...
Neuroviral Infections: RNA Viruses and Retroviruses presents an… ... Neuroviral Infections: RNA Viruses and Retroviruses presents an up-to-date overview of the general principles of infections and ... Rabies Virus Neurovirulence. Claire L. Jeffries, Ashley C. Banyard, Derek M. Healy, Daniel L. Horton, Nicholas Johnson, and ... major neuroviral infections caused by RNA viruses and retroviruses. It is designed for virologists, specialists in infectious ...
Thank you for your interest in spreading the word about Science Signaling.. NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.. ...
RNA viruses have similar shapes and perform similar functions as... ... Viruses that contain RNA as their genetic information are called RNA viruses, and of this family, Hepatitis C is a prime ... Viruses that contain RNA as their genetic information are called RNA viruses, and of this family, Hepatitis C is a prime ... However, RNA viruses are generally longer-lived than DNA viruses and target immune systems. RNA molecules are generally much ...
... drugs based on RNA compounds able to reduce viral replication levels and potentially applicable to all Influenza viruses, ... Since the RNA compounds rely on a sequence which is conserved among all Influenza (A, B and C) viruses, the RNA compounds can ... The antiviral RNA compounds proposed in this invention act on a very conserved mechanism within Influenza viruses that is ... Antiviral RNA compounds against Influenza viruses. Wageningen University is seeking commercial partners interested in ...
... a virus (such as a paramyxovirus or a retrovirus) whose genome consists of RNA. How to use RNA virus in a sentence. ... Comments on RNA virus. What made you want to look up RNA virus? Please tell us where you read or heard it (including the quote ... Post the Definition of RNA virus to Facebook Share the Definition of RNA virus on Twitter ... it is one of the RNA viruses, which are less well understood than are DNA viruses, and it has defied efforts to grow it in a ...
In this review, we summarize the current knowledge about how RNA viruses, including influenza virus, poliovirus, coxsackievirus ... In this review, we summarize the current knowledge about how RNA viruses, including influenza virus, poliovirus, coxsackievirus ... enterovirus 71, Japanese encephalitis virus, hepatitis C virus, and dengue virus, regulate these processes. We also discuss ... enterovirus 71, Japanese encephalitis virus, hepatitis C virus, and dengue virus, regulate these processes. We also discuss ...
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How do the apparent mutation rates of DNA viruses compare to those of RNA viruses and ii) why do related viruses eg. HIV-1 and ... Dear virologists, It is often assumed that RNA viruses should have high mutation rates resulting from viral RNA polymerases ... DNA/RNA virus mutation rates. Michael Goodin mgoodin at Tue Sep 2 23:21:58 EST 1997 *Previous message: hiv ... a many-trillionfold amplification of single RNA virus particles fails to overcome the Mullers ratchet effect (Duarte et al ( ...
C) RNA viruses were directly detected by RT-PCR from the total RNA of fecal sample 2: PMMV (lane 1), MCMV (lane 2), PBV, ... The human gut is known to be a reservoir of a wide variety of microbes, including viruses. Many RNA viruses are known to be ... RNA viral community in human feces: prevalence of plant pathogenic viruses.. Zhang T1, Breitbart M, Lee WH, Run JQ, Wei CL, Soh ... Here, we present a comparative metagenomic analysis of the RNA viruses found in three fecal samples from two healthy human ...
... beneficial in understanding how these inhibitors react and potentially help develop a new generation of drugs to target viruses ... with high death rates, like HIV-1, Zika, Ebola and SARS-CoV2, the virus that causes COVID-19. ... UNH researchers have identified new pathways in an RNA-based virus where inhibitors, like medical treatments, unbind. The ... many viruses have a genetic makeup of RNA molecules. These RNA-based genomes contain potential sites where inhibitors can ...
Of the two forms of G3BP, only G3BP1 is cleaved by a virus proteinase, 3Cpro, whereas G3BP2 is not cleaved by 3Cpro or 2Apro. ... Here we have screened all viral proteins for roles in inducing or inhibiting the formation of RNA granules by creating fusions ... the protease precursor 3CD and 3D polymerase all affect RNA granules to varying extents, whereas 2BC does not. 2Apro, which ... Viruses 2015, 7, 6127-6140. AMA Style. Dougherty JD, Tsai W-C, Lloyd RE. Multiple Poliovirus Proteins Repress Cytoplasmic RNA ...
Mechanisms and consequences of RNA virus persistent infections:. It is generally assumed that following acute infection RNA ... RNA virus persistence meeting: mechanisms and consequences August, 23 - 25, 2018, Institute of Virology, Medical Center - ... The purpose of this two-day conference is bringing together scientists working on many different viruses to address and ... discuss underlying general and specific questions concerning the mechanisms and consequences of persistent RNA virus infections ...
Solenopsis invicta virus 1,/i, (SINV-1), SINV-2, and SINV-3 are all positive, single-stranded RNA viruses and represent the ... A metagenomics approach successfully resulted in discovery of three viruses infecting ,i,S. invicta,/i,. ,i, ... single-stranded RNA viruses. ORF 1 was found to exhibit a characteristic helicase, protease, and RNA-dependent RNA polymerase ( ... Solenopsis invicta virus 1 (SINV-1), SINV-2, and SINV-3 are all positive, single-stranded RNA viruses and represent the first ...
RNA interference (RNAi) was recently suggested as a promising strategy for controlling insect pests, including those that serve ... Viruses 2016, 8, 329. AMA Style. Kanakala S, Ghanim M. RNA Interference in Insect Vectors for Plant Viruses. Viruses. 2016; 8( ... "RNA Interference in Insect Vectors for Plant Viruses." Viruses 8, no. 12: 329. ... virus induce gene silencing (VIGS) RNAi; dsRNA; plant viruses; insect vectors; insect pest control; virus induce gene silencing ...
Researchers at University of California San Diego School of Medicine have discovered that Zika virus infection leads to ... are made up of RNA instead of DNA. These viruses hijack the hosts cellular machinery to translate its RNA to proteins. Rana ... When Zika virus infects a human cell, Ranas team found, the cell modifies viral RNA with m6A as a means to get rid of the ... "After that, we decided to investigate m6A RNA in Zika virus as well, since we didnt want to miss out on this important ...
Optimization of feline immunodeficiency virus vectors for RNA interference.. Harper SQ1, Staber PD, Beck CR, Fineberg SK, Stein ... herpes simplex virus thymidine kinase promoter. A transfection control expression cassette consisting of the simian virus 40 ... RNA interference (RNAi) occurs naturally in plant and animal cells as a means for modulating gene expression. This process has ... FIV genes required for FIV virus production are indicated. The bipartite rev gene (not pictured) is located in env. The RRE ( ...
Beckman Coulter Life Sciences discusses the differences between RNA and DNA viruses in immunotherapy as well as related ... RNA viruses infect cells by injecting RNA into the cytoplasm of the host cells to transcribe and replicate viral proteins. RNA ... This includes positive-strand RNA viruses which are distinct from negative-strand RNA viruses, which require the added step of ... Unlike DNA viruses which must always transcribe viral DNA into RNA to synthesize proteins, RNA can skip the transcription ...
Regnum: Virus. Group IV: ssRNA(+) Ordo: Picornavirales Familia: Marnaviridae Genus: Marnavirus Species: Heterosigma akashiwo ... Retrieved from "" ...
The group of Negative-Stranded RNA Viruses (NSVs) includes many human pathogens, like the influenza, measles, mumps, ... These RNA-protein complexes or ribonucleoproteins function as templates for transcription and replication by action of the ... The genome of NSVs consists of one to several single-stranded, negative-polarity RNA molecules that are always assembled into ... Here we review our knowledge on these large RNA-synthesis machines, including the structure of their components, the ...
... have compiled a comprehensive new public database of genetic information to enable the detection and identification of RNA ... New database of PCR primers enables effective detection and identification of RNA viruses. *Download PDF Copy ... These in silico primers are capable of detecting 100% of the RNA viruses included in the latest U.S National Center for ... RNA viruses, which contain ribonucleic acid as their genetic material, cause many infectious diseases including influenza, ...
35 S RNA is a full-length transcript of the viral genome. It encodes the genes VII and I-V, arranged in tandem along the RNA, ... The cauliflower mosaic virus (CaMV) 35 S RNA is a full-length transcript of the viral genome. It encodes the genes VII and I-V ... Cauliflower mosaic virus 35 S RNA leader region inhibits translation of downstream genes. *Baughman G ... The reduced translation of gene I in the context of the 35 S RNA leader region was not due to the action of the gene VII ...
  • The replication of riboviruses whose chromosomes are composed of single-stranded RNA follows a simple scheme (Fig. 1 ). (
  • Wageningen University is seeking commercial partners interested in developing a new class of antiviral drugs based on RNA compounds able to reduce viral replication levels and potentially applicable to all Influenza viruses, including new pandemic strains. (
  • Once made dysfunctional, these RNA compounds can reduce viral genome transcription and replication levels and therefore the level of virus titers and the development of infection. (
  • RNA viruses are highly dependent on host cell machinery to fulfill their replication cycle and produce new progeny virus. (
  • In their paper , recently published in the Journal of Physical Chemistry Letters, the researchers looked specifically at an RNA fragment from the HIV-1 virus and its interaction with a ligand/inhibitor, a complex compound that is known to interfere with the virus replication process. (
  • Without m6A, the viral RNA was more stable and viral replication increased, as compared to human cells with normal methylation enzymes. (
  • These RNA-protein complexes or ribonucleoproteins function as templates for transcription and replication by action of the viral RNA polymerase and accessory proteins. (
  • Here we review our knowledge on these large RNA-synthesis machines, including the structure of their components, the interactions among them and their enzymatic activities, and we discuss models showing how they perform the virus transcription and replication programmes. (
  • Viruses have learned to manipulate the autophagic pathway to ensure their own replication and survival. (
  • We have selected some exemplary NS-RNA viruses and will describe how these NS-RNA viruses regulate autophagy and the role of autophagy in NS-RNA viral replication and in immune responses to virus infection. (
  • We also review recent advances in understanding how NS-RNA viral proteins perturb autophagy and how autophagy-related proteins contribute to NS-RNA virus replication, pathogenesis and antiviral immunity. (
  • Most of these viral glycoproteins synthesis and the replication enzymes offer a good inhibitory target for drug design against the ebola virus. (
  • The replication of Filoviridae family of viruses takes place in the cytoplasm of the host cell [ 6 , 7 ]. (
  • From a population standpoint, two main features characterize the replication of RNA viruses and viruses that use RNA as a replicative intermediate: high genetic variability, and enormous fluctuations in population size. (
  • Animal RNA viruses can be placed into about four different groups depending on their mode of replication. (
  • Positive-sense viruses have their genome directly utilized as if it were mRNA, producing a single protein which is modified by host and viral proteins to form the various proteins needed for replication. (
  • Hepatitis C virus (HCV) is a widespread human pathogen that in 80% cases establishes persistent replication in the liver [ 1 ]. (
  • Due to its central role in RNA viral replication, the non-structural protein 5 (NS5) RNA-dependent RNA-polymerase (RdRp) is a prime target for drug discovery. (
  • Both sets of mutations had little effect on virus growth in cultured cells, suggesting that the structure does not play a critical role in replication and other possible roles need to be identified. (
  • Because these properties are shared by certain bacteria ( rickettsiae , chlamydiae ), viruses are now characterized by their simple organization and their unique mode of replication. (
  • Other viruses, however, such as the herpesviruses , actually enter a time known as "viral latency," when little or no replication is taking place until further replication is initiated by a specific trigger. (
  • New insights on how subunits of the influenza virus polymerase co-evolve to ensure efficient viral RNA replication are provided by a study published October 3 in the PLOS Pathogens journal, by researchers from the Institut Pasteur and the CNRS (French National Center for Scientific Research). (
  • Enhancing fundamental knowledge about the RNA-polymerase of influenza viruses, which is an enzyme that consists of three subunits (i.e., a heterotrimer) and ensures transcription and replication of the viral genome, is essential to reach the goal of better prevention and treatment of disease. (
  • They showed that the polymerase subunits co-evolve to ensure not only optimal inter-subunit cooperation within the heterotrimer, but also proper levels dimerization - the process by which pairs of heterotrimers attach together -- which appears to be essential for efficient viral RNA replication. (
  • Importantly, all RNA viruses except retroviruses generate long, perfect dsRNA intermediates during replication of their RNA genome, and even dsDNA viruses generate high levels of perfect dsRNAs due to convergent transcription of both strands of their DNA genome. (
  • Because they most commonly arise from viral dsRNA replication intermediates, viral siRNAs should derive essentially equally from the viral RNA sense and antisense strands ( 6 ). (
  • During replication, RNA viruses rapidly generate diverse mutant progeny which differ in their ability to kill host cells. (
  • The family Flavivirdae has at least 68 viruses that have similar replication processes and are morphologically, morphogenetically, and biochemically similar (4). (
  • Since the virus is so small it can not carry all the necessary enzymes and proteins to complete its replication processes. (
  • Viruses with RNA as their genetic material which also include DNA intermediates in their replication cycle are called retroviruses, and comprise Group VI of the Baltimore classification. (
  • Some genes of RNA virus are important to the viral replication cycles and mutations are not tolerated. (
  • There are three distinct groups of RNA viruses depending on their genome and mode of replication: Double-stranded RNA viruses (Group III) contain from one to a dozen different RNA molecules, each coding for one or more viral proteins. (
  • Positive-sense ssRNA viruses (Group IV) have their genome directly utilized as mRNA, with host ribosomes translating it into a single protein that is modified by host and viral proteins to form the various proteins needed for replication. (
  • 3. DNA replication takes place in the nucleus while RNA replication takes place in the cytoplasm. (
  • Other implications for models of RNA tumor virus replication are also developed from these data. (
  • RNAs are formed when the viral RNA-dependent RNA polymerase complex switches, mid-replication, from one RNA molecule to another. (
  • RNA2 (R2) encodes the single virion structural protein whereas RNA1 (R1) encodes protein A, the viral RNA-dependent RNA polymerase (RdRP), and B2, a VSR ( 3 , 4 , 11 ) expressed after RNA1 replication from its own mRNA, RNA3 (Fig. s1). (
  • These data indicated that viral RNA replication in Drosophila embryos triggers an RNAi-mediated virus clearance in an Ago-2 -dependent manner and effective RNAi suppression by B2 is necessary to achieve normal accumulation of FHV RNAs. (
  • see nucleic acid nucleic acid, any of a group of organic substances found in the chromosomes of living cells and viruses that play a central role in the storage and replication of hereditary information and in the expression of this information through protein synthesis. (
  • The UCI and Dutch researchers examined one group of RNA viruses , called picornaviruses, using biochemical purification methods and confocal microscopy to see how they co-opt the functions of a cellular DNA repair enzyme called TDP2 to advance their replication process. (
  • Researchers from Florida hope to do just that by creating a compound that targets and binds to RNA regions on the SARS-CoV-2 genome and disrupts its replication. (
  • Prediction of RNA secondary structure of the 3'UTR revealed some previously unidentified conserved structures in the proximal region of the 3'UTR, the role of which in viral replication is still unknown. (
  • Unusually, expression of pipo depends not on ribosomes slipping into an alternative reading frame, but instead on the virus replication enzyme slipping during synthesis of a small percentage of the virus mRNAs. (
  • CPs have been shown to regulate the infection processes of RNA viruses, including RNA replication and gene expression. (
  • These RNA-based genomes contain potential sites where inhibitors can attach and deactivate the virus. (
  • In contrast to humans, the entire genomes of some viruses, including Zika and HIV, are made up of RNA instead of DNA. (
  • Top secret, viruses with RNA genomes! (
  • Today it is well known that viruses may contain DNA (poxvirus, mimivirus) or RNA (influenza virus, Zika virus), but for many years it was thought that genomes were only made of DNA. (
  • By the 1950s many viruses had been isolated which we now know have genomes of DNA (bacteriophage, poxvirus) or RNA (yellow fever virus, poliovirus, influenza virus). (
  • Here we outline a next-generation RNA sequencing protocol that enables de novo assemblies and intra-host variant calls of viral genomes collected from clinical and biological sources. (
  • They did so with the RNA genomes of five influenza (Flu) A viruses, including seasonal influenza A and avian influenza A viruses. (
  • However, while the genomes of people and other living things consist of DNA, some things that aren't technically "living," such as viruses, have genomes coded by RNA instructions instead. (
  • Rambo-Martin's work translated the data into something that made sense, and he was able to confirm that the molecular work performed did, in fact, sequence the RNA genomes of the influenza viruses studied. (
  • There are many examples of viruses with segmented genomes - like influenza viruses - but these genomes segments are packaged in one virus particle. (
  • Sequence analysis of viruses isolated from Culex mosquitoes in Central and South American Countries revealed six new viruses with segmented RNA genomes, which was confirmed by gel electrophoresis of RNA extracted from virus particles. (
  • RNA viruses with segmented genomes are common, but in this case, the surprise came when it was found that the dose-response curve of infection for these viruses was not linear. (
  • They are part of a clade of RNA viruses with segmented genomes called the Jingmenvirus, which includes a novel tick-borne virus isolated in China ( previously discussed on this blog ), and a variant isolated from a red colobus monkey in Uganda. (
  • These viruses are also likely to have genomes that are separately packaged. (
  • How such viral genomes emerged and persisted remains a mystery that might be solved by the analysis of other viruses with similar genome architectures. (
  • RNA viruses use various strategies to condense their genetic information into small genomes. (
  • Viruses that possess single-stranded, mRNA-sense genomes are called positive-strand RNA viruses. (
  • While most mRNAs in eukaryotic cells are monocistronic, positive-strand RNA viruses encode multiple proteins in single polycistronic genomes. (
  • Double-stranded RNA viruses (dsRNA viruses) are a polyphyletic group of viruses that have double-stranded genomes made of ribonucleic acid. (
  • The genomes of these viruses consist of 10 to 12 segments of dsRNA, each generally encoding one protein. (
  • In this project we identified a number of potential RNA structures in picornavirus genomes and started to analyse one of these structures. (
  • We also describe other translation strategies used by plant viruses to optimize the usage of the coding capacity of their very compact genomes, including leaky scanning initiation, ribosomal frameshifting and stop-codon readthrough. (
  • Viral mRNA translation is a paradigmatic illustration of this, as the hallmark of viruses is that their genomes do not code for a protein synthesis apparatus. (
  • So, in addition to producing prodigious amounts of the raw material of evolution (mutations), these viruses also possess mechanisms that, in principle, allow them both to purge their genomes of accumulated deleterious changes (Muller, 1964) and to create or spread bene locial combinations of mutations in an efficient manner (Fisher, 1930;Muller, 1932), two processes which are not available to clonal organisms. (
  • All RNA viruses have relatively high mutation rates, making their genomes highly variable. (
  • Many of the most important RNA viruses were amongst the first genomes to be sequenced, some 30-40 years ago. (
  • Besides protein-coding genes, RNA virus genomes are also packed full of other functional elements - for example the RNA of the genome can fold into complex 3-dimensional structures that form important signals to direct the different aspects of the viral replicative cycle. (
  • Computational analysis of virus genomes provides a practical and cost-effective way forward that can be used to precisely and efficiently target follow-up experimental research. (
  • The overarching goal of the project is to leverage the vast quantity of virus genome sequencing data available, using state-of-the-art computational techniques, to systematically identify functional elements in RNA virus genomes. (
  • This review focuses on the regulatory roles that phosphorylation of CPs has in the life cycle of viruses with RNA genomes. (
  • To date, most of the drugs against viruses act as direct-antivirals, meaning that compounds are designed to directly target viral proteins. (
  • Here we have screened all viral proteins for roles in inducing or inhibiting the formation of RNA granules by creating fusions with mCherry and expressing them individually in cells. (
  • Expression of viral proteins separately revealed that the capsid region P1, 2A pro , 3A, 3C pro , the protease precursor 3CD and 3D polymerase all affect RNA granules to varying extents, whereas 2BC does not. (
  • In human cells, RNA is the genetic material that carries instructions from the DNA in a cell's nucleus out to the cytoplasm, where molecular machinery uses those instructions to build proteins. (
  • These viruses hijack the host's cellular machinery to translate its RNA to proteins. (
  • RNA viruses infect cells by injecting RNA into the cytoplasm of the host cells to transcribe and replicate viral proteins. (
  • Unlike DNA viruses which must always transcribe viral DNA into RNA to synthesize proteins, RNA can skip the transcription process. (
  • This includes positive-strand RNA viruses which are distinct from negative-strand RNA viruses, which require the added step of mRNA transcription before they can be translated to proteins. (
  • I. European patent No. 0 846 181 with the title 'cDNA corresponding to the antigenome of nonsegmented negative strand RNA viruses, and process for the production of such viruses encoding additional antigenically active proteins' was granted on European patent application No. 96928446.2 (published as WO 97/06270). (
  • Messenger RNA is a kind of intermediary that tells the body how to convert the instructions contained in the genome into actual proteins. (
  • In recent years, remarkable progress has been made in determining, at atomic and subnanometeric levels, the structures of a number of key viral proteins and of the virion capsids of several dsRNA viruses, highlighting the significant parallels in the structure and replicative processes of many of these viruses. (
  • The positive-sense RNA molecule then acts as viral mRNA, which is translated into proteins by the host ribosomes . (
  • The resultant protein goes on to direct the synthesis of new virions, such as capsid proteins and RNA replicase, which is used to produce new negative-sense RNA molecules. (
  • Based on these data, redox-sensitive posttranslational modifications of HCV NS5B and other proteins merit a more detailed investigation and analysis of their role(s) in the virus life cycle and associated pathogenesis. (
  • The positive-strand RNA may be used as messenger RNA (mRNA) which can be translated into viral proteins by the host cell's ribosomes. (
  • Within the host cell the genetic material of a DNA virus is replicated and transcribed into messenger RNA by host cell enzymes, and proteins coded for by viral genes are synthesized by host cell ribosomes. (
  • In viruses that have membranes, membrane-bound viral proteins are synthesized by the host cell and move, like host cell membrane proteins, to the cell surface. (
  • Some viruses have only a few genes coding for capsid proteins. (
  • Although in general viruses "steal" their lipid envelope from the host cell, virtually all of them produce "envelope proteins" that penetrate the envelope and serve as receptors. (
  • 2016 ). From a strategic point of view, understanding how viruses translate their own proteins may significantly contribute to the identification of therapeutic (Robert et al. (
  • DNA here acts as a pattern for RNA virus then transcribes it into viral proteins. (
  • In the test, CRISPR Cas13 proteins are "programmed" to recognize segments of SARS-CoV-2 viral RNA and then combined with a probe that becomes fluorescent when cleaved. (
  • When the Cas13 proteins are activated by the viral RNA, they start to cleave the fluorescent probe. (
  • In this study, we present a series of experiments showing a significant reduction in hepatitis B virus (HBV) transcripts and proteins in cell culture, as well as in the viral replicative forms, induced by siRNA-producing vectors. (
  • The results showed several unique and interesting features of the s2m RNA, including a distinctive fold that appears to be capable of binding to certain proteins involved in regulating protein synthesis in cells. (
  • Messenger RNA is the intermediary that carries genetic information from the DNA in the chromosomes to the cellular protein factories, called ribosomes, where the genetic information is translated into proteins. (
  • The SARS s2m RNA is in an untranslated section at one end of each of the messenger RNAs that direct the production of viral proteins in infected cells. (
  • This part of the ribosome and the proteins that bind to it are involved in the regulation of protein synthesis, leading Scott and his coauthors to hypothesize that the s2m RNA, by mimicking the ribosomal binding site, may serve to hijack the host cell's protein-synthesis machinery for use by the virus. (
  • Finally, a cDNA fragment of 3,737 bp was obtained, which showed homology to viral proteins, particularly to the RNA-dependent RNA polymerase of members of the family Bunyaviridae , but without high similarity to a known genus. (
  • Measles (rubeola) is an infectious disease caused by multiplication of a single-strand ribonucleic acid (RNA) virus of the genus Morbillivirus in the upper respiratory tract and conjunctiva. (
  • RNA, or ribonucleic acid, is a family of biological molecules that function in gene synthesis, regulation and expression. (
  • RNA viruses, which contain ribonucleic acid as their genetic material, cause many infectious diseases including influenza, polio and measles. (
  • Ebola, also known as Ebola virus disease (EVD/EBOV) and Ebola hemorrhagic fever (EHF) in the past, is a filamentous, enveloped, non-segmented, single stranded negative sense ribonucleic acid (RNA) virus [ 4 ]. (
  • An RNA virus is a virus that has ribonucleic acid (RNA) as its genetic material and does not replicate using a DNA intermediate. (
  • RNA or ribonucleic acid is a nucleic polymer acid that performs a significant role in translating the genetic code from the DNA to protein products. (
  • The enzyme makes RNA (ribonucleic acid) from a DNA template. (
  • In contrast, most viruses house essential genetic information in DNA molecules. (
  • RNA molecules are generally much less stable and unpredictable than DNA molecules. (
  • RNA and DNA are both molecules containing the genetic information that is necessary for life. (
  • Positive in vitro and ex vivo results to date suggest that this new RNA molecules will show greater efficacy against pandemic virus strains. (
  • Similar to how humans are made up of a series of different chromosomes, known as DNA, many viruses have a genetic makeup of RNA molecules. (
  • They are also developing small molecules to target specific RNA structures as a means to treat Zika virus infections. (
  • Furthermore, some RNA molecules can act as mRNA being translated directly into protein. (
  • The genome of NSVs consists of one to several single-stranded, negative-polarity RNA molecules that are always assembled into mega Dalton-sized complexes by association to many nucleoprotein monomers. (
  • Double-stranded reoviruses contain up to a dozen different RNA molecules which each code for an mRNA. (
  • The first, reassortment, occurs only in multipartite viruses and involves swapping one or more of the discrete RNA molecules that make up the segmented viral genome. (
  • Today I'm writing about another fun kind of loop: circular RNA molecules. (
  • These are formed when RNA molecules transcribed from linear DNA undergo the processing necessary to become efficient protein assembly manuals. (
  • Most of the time the excess RNA is degraded, but sometimes this processing, known as splicing, yields circular RNA molecules, or circRNAs. (
  • We first noticed something odd when we were exploring whether we could use circular RNA molecules to drive the expression of genes in mammalian cells. (
  • CircRNA produced from the type of splicing used by human cells is accepted, while the same molecule produced by a kind of splicing used by viruses induces the expression of immune signaling molecules called cytokines that protect it and neighboring cells from viral infections. (
  • Because circRNAs were first discovered in viruses (the hepatitis D genome is a single RNA circle), it appears that mammalian cells have devised a way to recognize viral-born circRNAs and mobilize immune molecules to fight off infection. (
  • The nanoparticle, constructed from a three-way junction (3WJ) motif of packaging RNA (pRNA) molecules, can serve as a platform for building larger, multifunctional nanoparticles, says Guo, which can then be injected into the body to deliver therapeutics to targeted cells. (
  • In addition, each arm of the 3WJ core can be fused to siRNA molecules, receptor-binding ligands and RNA aptamers, molecular tools necessary for the nanoparticle to find a targeted cell inside the body and silence genes within it. (
  • FHV contains an RNA genome ( 10 ) divided among two plus-strand molecules, RNAs 1 and 2. (
  • To study the binding capacity of different molecules, the team investigated a library of 3,271 RNA-focused ligands using microarrays. (
  • De med positiv polaritet kan oversette RNA-molekylet sitt direkte til protein, mens de med negativ polaritet først må skrive det av til budbærer-RNA før de kan omsette det til protein . (
  • Both DNA and RNA are long protein-based polym. (
  • The unfolded protein response in virus infections. (
  • Cells can chemically modify RNA to influence protein production. (
  • The new DGIST reference resource, the MTPrimerV database, contains 152, 380, 247 PCR primer pairs for the detection of 1,818 viruses, covering 7,144 gene-coding sequences or CDSs (from coding DNA sequence), which are the portion of a gene's DNA or RNA that codes for a protein. (
  • These in silico primers are capable of detecting 100% of the RNA viruses included in the latest U.S National Center for Biotechnology Information Reference Sequence (NCBI RefSeq) database, an open access curated collection of DNA and RNA nucleotide sequences and their protein products. (
  • Watson and Crick proposed the double-helical structure of DNA in 1953, and a few years later published the Central Dogma, which suggested that information flowed in biological systems from DNA to RNA to protein. (
  • But Stanley and others thought TMV was a protein, and that the RNA was either a contaminant, or played a structural role. (
  • A structural role for RNA was reinforced as late as 1955 when Heinz Fraenkel-Conrat separately purified TMV protein and RNA. (
  • However, RNA also has a structural role in TMV virus particles, as it organizes the capsid protein (yellow in illustration at left) into regularly repeated subunits. (
  • Dei med positiv polaritet kan setja om RNA-molekylet sitt direkte til protein , medan dei med negativ polaritet fyrst lyt skriva det av til bodberar-RNA før dei kan setja det om til protein. (
  • The genomic RNA is non-contagious alone because it is not able to serve as a template for protein synthesis [ 6 , 7 ]. (
  • To start the transcription of positive-sense messenger RNA (mRNA) the viral protein must connect with the genomic RNA [ 6 , 7 ]. (
  • PIPO is expressed as a fusion protein with the N-terminal half of P3 (P3N-PIPO) via transcriptional slippage of viral RNA-dependent RNA polymerase (RdRp). (
  • Here, we report that one of such redox switches is the NS5B protein that exhibits RNA-dependent RNA polymerase (RdRp) activity. (
  • Since 2011, multiple compounds that target enzymatic activity and/or functions of the HCV protease (NS3 protein), RNA-dependent RNA polymerase (RdRp, NS5B protein), and the regulatory NS5A protein were approved for the treatment of CHC [ 4 ]. (
  • Apart from RdRp, viruses in Duplornaviricota also share icosahedral capsids that contain 60 homo- or heterodimers of the capsid protein organized on a pseudo T=2 lattice. (
  • A virus consists of genetic material, which may be either DNA or RNA, and is surrounded by a protein coat and, in some viruses, by a membranous envelope. (
  • No equivalent of the protein stacking platform observed for the priming nucleotide in the phi6 enzyme is present in HCV polymerase, however, again suggesting that a change in conformation of the thumb domain takes place upon template binding to allow for efficient de novo initiation of RNA synthesis. (
  • For example, the region of the hepatitis C virus genome that encodes the core protein is highly conserved, because it contains an RNA structure involved in an internal ribosome entry site. (
  • The new diagnostic test takes advantage of the CRISPR Cas13 protein, which directly binds and cleaves RNA segments. (
  • Molecular mimicry in diabetes mellitus: the homologous domain in coxsackie B virus protein 2C and islet autoantigen GAD65 is highly conserved in the coxsackie B-like enteroviruses and binds to the diabetes associated HLA-DR3 molecule. (
  • Guo has pioneered RNA nanotechnology since 1998, when his lab discovered that RNA nanoparticles in the bacteriophage phi29 virus can be constructed by self-assembly using re-engineered fragments to gear a nanomotor to power DNA into the virus protein shell. (
  • The small RNAs are assembled with an Argonaute (Ago) protein into related effector complexes, such as RNA-induced silencing complex (RISC), to guide specific RNA silencing ( 1 ). (
  • Their findings suggest that it may help the virus hijack the protein-building machinery of infected cells. (
  • This protein, called NS5B, forms the active site of the virus's RNA-dependent RNA polymerase enzyme. (
  • To find a novel influenza inhibitor targeting the endonuclease activity of influenza A virus polymerase acidic protein (PA), which is essential for the acquisition of primers for viral mRNA transcription, seven Kampo extracts were tested in vitro for their ability to inhibit endonuclease activity of the recombinant PA protein that was expressed and purified from Escherichia coli . (
  • Surprisingly, however, ""hidden"" protein-coding genes are still being discovered even in some of the most well-studied RNA viruses. (
  • This allows the virus to modulate the efficiency of frameshifting as the amount of virus protein changes over time in an infected cell and thus regulate virus gene expression. (
  • Recently, Tomato spotted wilt virus (TSWV) nonstructural protein NSs has been identified unambiguously as an avirulence (Avr) determinant for Tomato spotted wilt ( Tsw )-based resistance. (
  • New antiviral drug design leading to transcriptional reduction of Influenza viral genomic RNA segments. (
  • We have designed a test by taking advantage of the high genomic mutation rate and short generation time of RNA viruses. (
  • Their observations reveal that influenza polymerase dimerization as a feature that can restrict the reassortment of genomic viral RNA segments, a major evolutionary mechanism of influenza viruses, and could become an attractive target for antiviral drug development. (
  • The 5'-untranslated genomic region of the contaminant pestivirus RNA were amplified by reverse transcription-PCR and sequenced. (
  • Part of our work involves developing new comparative genomic techniques for virus genome analysis. (
  • Positive clones were further analysed by using them as hybridisation probes in Northern blots of total plant RNA and in Southern hybridisation with genomic DNA from Sorbus aucuparia leaves. (
  • Current options to reduce the impact of Influenza virus infections include vaccination and the use of antiviral drugs. (
  • Antiviral drugs have the advantage to be immediately applicable and thereby may help to contain an emerging pandemic virus at its emergence. (
  • The antiviral RNA compounds proposed in this invention act on a very conserved mechanism within Influenza viruses that is different from the currently available classes of emerging drugs, thus offering possibilities for new antiviral drug design and for solutions to the above described limitations. (
  • Since the RNA compounds rely on a sequence which is conserved among all Influenza (A, B and C) viruses, the RNA compounds can be functional as antiviral drug against all Influenza viruses, including new, emerging pandemic strains. (
  • The overall objective of this project is to provide basic knowledge on molecular events of RNA virus infections and to develop novel antiviral strategies to battle against several highly pathogenic RNA viruses such as Zika, CCHF, and Ebola virus. (
  • Eleutherococcus senticosus root extract exhibits antiviral activity against rhinovirus, respiractory syncytial virus and influenza A virus in cell cultures. (
  • The current Zika virus (ZIKV) outbreak became a global health threat of complex epidemiology and devastating neurological impacts, therefore requiring urgent efforts towards the development of novel efficacious and safe antiviral drugs. (
  • This comprehensive compilation of the altered gene expression profiles and signal transduction pathways in host cells in response to the majority of human/animal RNA viruses opens new directions for basic and clinical research on viral pathogenesis, and also provides valuable biomarkers for researchers to select gene targets in the development of diagnostic tests and antiviral therapeutics for a number of infectious diseases. (
  • The question of whether any mammalian cells are able to mount an effective RNA interference-mediated antiviral innate immune response has remained highly controversial. (
  • However, the more likely explanation for the existence of RNAi is that it initially evolved as an antiviral innate immune response, and some of the first siRNAs to be described were detected at high levels in plants infected with potato virus X ( 3 ). (
  • In considering whether mammalian cells are also able to process viral dsRNAs into antiviral siRNAs, it is important to take into account the defining characteristics of such siRNAs in other systems, especially insects, to ensure that viral RNA degradation products are not erroneously described as siRNAs. (
  • RNA silencing provides an antiviral mechanism in plants and animals ( 2 - 6 ). (
  • However, it is unknown if antiviral silencing in plants is controlled by a specific small RNA pathway targeted by plant VSRs. (
  • Introductory chapters describe where viruses fit into the world of microorganisms, explore the unique properties of DNA and RNA viruses , and show how new antiviral drugs are discovered and developed into useful medicines. (
  • Research on the genome of the virus that causes severe acute respiratory syndrome (SARS) has revealed an unusual molecular structure that looks like a promising target for antiviral drugs. (
  • The structure itself also provides a starting point for designing antiviral drugs that might bind to this RNA and prevent it from doing whatever it is that is vital to the life cycle of the virus. (
  • The vast majority of the 36,769 viral sequences obtained were similar to plant pathogenic RNA viruses. (
  • [1] Notable human pathogenic RNA viruses include SARS , Influenza and Hepatitis C . (
  • 1 DNA viruses such as adenoviruses and poxviruses are more likely to be double-stranded whereas most RNA viruses are single-stranded. (
  • For decades, scientists who wanted to research the genome of RNA viruses, such as influenza, had to do so using an indirect and time-consuming method that involved first converting the single-stranded RNA into double-stranded DNA. (
  • Their nucleic acid is usually single-stranded RNA (ssRNA) but may be double-stranded RNA (dsRNA). (
  • The double-stranded (ds)RNA viruses represent a diverse group of viruses that vary widely in host range (humans, animals, plants, fungi , and bacteria ), genome segment number (one to twelve), and virion organization (T-number, capsid layers, or turrets). (
  • One of these includes RNA replicase , which copies the viral RNA to form a double-stranded replicative form, in turn this directs the formation of new virions. (
  • Reverse transcriptase , a viral enzyme that comes from the virus itself after it is uncoated, converts the viral RNA into a complementary strand of DNA, which is copied to produce a double stranded molecule of viral DNA. (
  • Double-Stranded RNA Virus: Host Signaling Responses to Reovirus Infection (D Pan et al. (
  • The double-stranded genome is used to transcribe a positive-strand RNA by the viral RNA-dependent RNA polymerase (RdRp). (
  • The positive-strand RNA can also be replicated by the RdRp to create a new double-stranded viral genome. (
  • Double-stranded RNA viruses are classified in two separate phyla Duplornaviricota and Pisuviricota (specifically class Duplopiviricetes), which are in the kingdom Orthornavirae and realm Riboviria. (
  • Double-stranded RNA viruses evolved two separate times from positive-strand RNA viruses. (
  • Double-stranded RNA viruses include the rotaviruses, known globally as a common cause of gastroenteritis in young children, and bluetongue virus, an economically significant pathogen of cattle and sheep. (
  • in 1998 ( 1 ), RNA interference (RNAi) is a cellular response whereby introduction of long, perfect double-stranded RNAs (dsRNAs) into cells results in the posttranscriptional inhibition of endogenous mRNAs that are perfectly complementary to the dsRNAs. (
  • One of these includes RNA-dependent RNA polymerase (RNA replicase), which copies the viral RNA to form a double-stranded replicative form. (
  • 1. DNA viruses are mostly double-stranded while RNA viruses are single-stranded. (
  • RNA interference (RNAi) is the process whereby double-stranded RNA (dsRNA) induces the sequence-specific degradation of homologous messenger RNA (mRNA).4 This process is mediated by 21 to 23 nucleotides, called small interfering RNAs (siRNA), cleaved from dsRNA. (
  • RNA interference (RNAi) is the process of sequence-specific gene silencing, initiated by double-stranded RNA (dsRNA) that is homologous in sequence to the target gene. (
  • Our work also describes a molecular framework for the viral immunity, in which viral double-stranded RNA produced during infection acts as the pathogen trigger whereas Drosophila Dicer-2 and Argonaute-2 act as host sensor and effector, respectively. (
  • Double-stranded RNA pattern and partial sequence data indicate plant virus infection associated with the ringspot disease of European mountain ash ( Sorbus aucuparia L. (
  • Double-stranded RNA (dsRNA) has been extracted from tissue of European mountain ash trees ( Sorbus aucuparia L.) showing typical ringspot and mottling symptoms on leaves and a gradual decay in general. (
  • Establishing persistent infection likely involves a number of molecular, cellular and immunological determinants, including the genetics of the viruses, the genetics of their hosts and potential new host species, and many environmental factors, such as other microorganisms. (
  • and (iv) the small interfering RNA/microRNA-mediated gene silencing pathway, a recently characterized new host defense mechanism against viral infection.Organized into 27 highly accessible and well-illustrated chapters, this volume explores state-of-the-art knowledge of the molecular mechanisms of RNA virus infection and host-virus interactions. (
  • Development of an internally controlled real-time reverse transcriptase PCR assay for pan-dengue virus detection and comparison of four molecular dengue virus detection assays. (
  • RNA structures play important roles in picornavirus molecular biology and recent evidence suggests that these are more extensive than previously thought. (
  • Such long, perfect dsRNAs, which are not normally found in uninfected cells, therefore function not only as potential substrates for siRNA biogenesis but also as an important pathogen-associated molecular pattern (PAMP) that alerts eukaryotic cells to the presence of an invading virus. (
  • All of the authors are affiliated with UCSC's Center for Molecular Biology of RNA. (
  • This is a great example of interdisciplinary science at work," said Harry Noller, Sinsheimer Professor of Molecular Biology at UCSC and director of the RNA center. (
  • It hangs on the tail end of the messenger RNA like a little molecular knob," Noller said. (
  • Hepatitis C virus enzyme, molecular model. (
  • A key step towards developing effective treatments and/or control strategies for viruses is to first achieve a solid understanding of their molecular biology. (
  • By enhancing our understanding of the molecular biology of many virus species, the project lays essential ground work for follow-up advances in diverse virus control strategies. (
  • The computational analysis is coupled with laboratory follow-up work to fully characterize the most important computational findings, ranging from novel features in important viruses, to novel molecular mechanisms with potential biotechnology applications. (
  • It is generally assumed that following acute infection RNA viruses are effectively cleared by the immune system. (
  • Human cells modify viral RNA with m6A as a means to get rid of the infection. (
  • Researchers at University of California San Diego School of Medicine have discovered that Zika virus infection leads to modifications of both viral and human genetic material. (
  • When Zika virus infects a human cell, Rana's team found, the cell modifies viral RNA with m6A as a means to get rid of the infection. (
  • In addition, they found that this host response to Zika viral infection also induced specific m6A modifications on human RNA. (
  • To unravel the role of m6A in Zika virus infection of human cells growing in the laboratory, the researchers removed the human enzymes responsible for adding methyl groups to viral RNA. (
  • Although reassortment was not detected in this Nairobi Sheep Disease Virus co-infection, a potential risk for emergence of a new pan- demic strain by reassortment between these 2 viruses RNA in Ixodid Ticks, (with humans as mixing vessels) should not be ignored. (
  • To reduce the risk for emergence of new viral subtypes, the public health and scientific communities should en- Shangshu Gong,1 Biao He,1 Zedong Wang,1 hance surveillance for co-infection with influenza (H7N9) Limin Shang, Feng Wei, Quan Liu, Changchun Tu virus and other influenza virus subtypes. (
  • Human co-infection new livestock or transport of animals through these areas with avian influenza and seasonal influenza viruses, China. (
  • This scientific achievement may shed light upon how influenza viruses function, their lifecycle, and how they change during the course of infection. (
  • These findings indicate that the viral RNA segments are separately packaged, and must enter a cell together to initiation infection. (
  • An interesting question is to identify the selection that lead to the emergence of multicomponent viruses that require multiple particles to initiate an infection. (
  • In this review, we briefly introduce autophagy, viral xenophagy and the interaction among autophagy, virus and immune response, then focus on the interplay between NS-RNA viruses and autophagy during virus infection. (
  • As such, purified RNA of a positive-sense virus can directly cause infection though it may be less infectious than the whole virus particle. (
  • While Dcr1 is essential for insect viability, Dcr2 is dispensable, thus allowing the experimental demonstration that Dcr2-deficient fruit flies are hypersusceptible to infection by a range of viruses. (
  • Research has also shown that infection of West Nile could involve the fusion of the virus straight to the host cell's plasma membrane (13). (
  • Stored sera from a population of individuals, who tested positive for hepatitis C infection as part of the NHANES III (1988-1994) survey, were analyzed for the presence of hepatitis C virus (HCV) RNA. (
  • The prevalence of hepatitis C virus infection in the United States, 1988 through 1994. (
  • Unlike many other tests that are available, this test also gives an estimate of viral load, or the number of virus particles in a sample, which can help doctors monitor the progression of a COVID-19 infection and estimate how contagious a patient might be. (
  • Additionally, persistent infection by some RNA viruses can induce or enhance accelerated immune activation. (
  • The two most prevalent RNA viruses causing chronic infection, hepatitis C virus and human immunodeficiency virus type 1 (HIV-1), are both associated with autoimmune disorders. (
  • McMurray RW, Elbourne K. Hepatitis C virus infection and autoimmunity. (
  • Extrahepatic manifestations of chronic hepatitis C virus infection. (
  • This finding suggests that we could possibly protect cells from viral infection by using circular RNAs. (
  • Hepatitis B virus (HBV) is a 3.2-kb DNA virus, replicating almost exclusively in the liver.1 Although effective recombinant vaccines are available, HBV infection is still a major global health problem: Each year, acute and chronic HBV infection causes about 1 million deaths. (
  • Here, we demonstrate that an RNA interference pathway protects adult flies from infection by two evolutionarily diverse viruses. (
  • Plant viruses have evolved diverse strategies for evading the RNA silencing immunity and expression of viral suppressors of RNAi (VSRs) is essential for infection and virulence ( 6 ). (
  • Here we investigated if RNAi indeed provides protection against virus infection in Drosophila embryos and adults. (
  • This assay will enable continued studies of the shedding and transmission of measles virus and, it is hoped, will provide a rapid means to identify measles infection, especially in mild or asymptomatic cases. (
  • The complete 3'UTR of DENV-1 was sequenced from 13 patients suffering from the severe form of dengue virus infection (dengue hemorrhagic fever). (
  • We are also taking some of the most interesting newly discovered features into the lab to experimentally characterize exactly what their function is during virus infection. (
  • RNA interference (RNAi) was recently suggested as a promising strategy for controlling insect pests, including those that serve as important vectors for plant pathogens. (
  • Optimization of feline immunodeficiency virus vectors for RNA interference. (
  • RNA interference (RNAi) occurs naturally in plant and animal cells as a means for modulating gene expression. (
  • RNA interference (RNAi) silences gene expression through small interfering RNAs (siRNAs) and microRNAs (miRNAs). (
  • Mutation of a GW/WG motif (position 17/18) rendered NSs completely dysfunctional for RSS and Avr activity, and indicated a putative interaction between NSs and Argonaute 1 (AGO1), and its importance in TSWV virulence and viral counter defence against RNA interference. (
  • This enables RNA and DNA viruses to reproduce genetic material and create protective coatings, or capsids, before exiting through cell walls. (
  • One variety of viruses have sensory strands of RNA as their genetic material, while the other variety contains antisense strands that pair with opposites. (
  • DNA is a stable, double helix that functions in long-term storage of genetic material, while RNA is a reactive, single helix that transfers information. (
  • But it was the first virus discovered - tobacco mosaic virus, in the 1890s - that lead the way to establishing RNA as genetic material. (
  • To everyone's surprise she found that TMV RNA itself was infectious , proving in 1957 that it was the viral genetic material. (
  • By the early 1950s the idea that RNA could be viral genetic material was clearly in the minds of virologists, hence Ephrussi-Taylor's amusing letter on influenza virus and poliovirus. (
  • RNA viruses generally have very high mutation rates as they lack DNA polymerases which can find and fix mistakes, and are therefore unable to conduct DNA repair of damaged genetic material. (
  • Because host cells do not have the ability to replicate "viral RNA" but are able to transcribe messenger RNA, RNA viruses must contain enzymes to produce genetic material for new virions. (
  • Over the last two decades it has become increasingly clear that many RNA viruses add the capacity to exchange genetic material with one another, and to acquire genes from their hosts, to this evolutionary repertoire. (
  • The SARS virus is a type of RNA virus, meaning that its genetic material is RNA rather than the more familiar DNA found in the chromosomes of everything from bacteria to humans. (
  • After genome sequencing, West Nile Virus (lineage II strain 956) was determined to have 10,962 nucleotides with a GC content of 51%, 93% of the RNA is coding, the topology is linear, and it is a ssRNA molecule (2). (
  • A second process, recombination, can occur ineither segmented or unsegmented viruses when `donor'nucleotide sequence is introduced into a single, contiguous ` acceptor ' RNA molecule to produce a new RNA containing genetic information from more than one source. (
  • When the compound was tested with other highly expressed messenger RNAs (mRNAs), they did not bind with C5-Chem-CLIP, indicating that the molecule is selective. (
  • Even so, the results demonstrate the feasibility of RNA-targeted small-molecule drugs in the future. (
  • Positive-sense viral RNA is identical to viral mRNA and thus can be immediately translated by the host cell. (
  • Negative-sense viral RNA is complementary to mRNA and thus must be converted to positive-sense RNA by an RNA polymerase before translation. (
  • In the Baltimore classification system, which groups viruses together based on their manner of mRNA synthesis, dsRNA viruses are group III. (
  • One strand of the siRNA duplex is then essentially randomly loaded into the RNA-induced silencing complex RISC, where it serves as a guide RNA to direct RISC to complementary mRNA targets. (
  • In vitro studies have documented the interactions between human lymphocytes and viruses, through which viral infections lead to an aberrant control of immune responses, and to subsequent diseases. (
  • Neuroviral Infections: RNA Viruses and Retroviruses presents an up-to-date overview of the general principles of infections and major neuroviral infections caused by RNA viruses and retroviruses. (
  • Furthermore, the emergence and re-emergence of infectious diseases may be determined by persistent infections in the human community as well as in wild and domestic animal populations, potentially increasing the zoonotic potential of some viruses. (
  • The purpose of this two-day conference is bringing together scientists working on many different viruses to address and extensively discuss underlying general and specific questions concerning the mechanisms and consequences of persistent RNA virus infections with an emphasis on zoonotic aspects. (
  • The feasibility of using high resolution genome many other viral pathogens and therefore pose a major sequencing of influenza A viruses to detect mixed infections and threat to public health ( 6 , 7 ). (
  • This is the first comprehensive book on human/animal gene responses to RNA viral infections, including prevalent, emerging and re-emerging RNA viruses such as HIV, SARS-CoV, West Nile virus, influenza virus and many others. (
  • Coppieters KT, Boettler T, von Herrath M. Virus infections in type 1 diabetes. (
  • RNA nanoparticles have applications in treating cancers and viral infections," he says, "but one of the problems in the field is that RNA nanoparticles are relatively unstable. (
  • A previous analysis of mutation rates in RNA viruses (specifically in riboviruses rather than retroviruses) was constrained by the quality and quantity of available measurements and by the lack of a specific theoretical framework for converting mutation frequencies into mutation rates in this group of organisms. (
  • RNA viruses also include retroviruses which use reverse transcriptase to create DNA from RNA templates. (
  • Retroviruses integrate a DNA intermediate of their RNA genome into the host genome, and therefore have a higher chance of correcting any mistakes in their genome thanks to the action of proof-reading DNA polymerases belonging to the host cell. (
  • Retroviruses are single-stranded but unlike other single-stranded RNA viruses they use DNA intermediates to replicate. (
  • Overall organisation of NSV RNA synthesis machines. (
  • Recently, a new vector system called pSUPER (suppression of endogenous RNA), which directs the synthesis of siRNAs and persistently suppresses gene expression in mammalian cells, has been developed. (
  • This means that the virus must bring along with it the RNA-dependent RNA polymerase enzyme. (
  • For certain viruses the RNA is replicated by a viral enzyme ( transcriptase ) contained in the virion, or produced by the host cell using the viral RNA as a messenger. (
  • We now know that the injected dsRNAs are processed by the cytoplasmic RNase III enzyme Dicer into ∼22-bp dsRNA duplexes, called small interfering RNAs (siRNAs) ( 2 ). (
  • Some RNA viruses embed transcriptase enzyme that transfer RNA virus to DNA virus and combine into the host DNA. (
  • 'With chemical modification, stable RNA nanoparticles go 3-D ' ), the risk posed by RNase, a common enzyme that quickly degrades RNA upon contact. (
  • Recombination occurs in many RNA viruses and can be of major evolutionary significance. (
  • However, rates of recombination vary dramatically among RNA viruses, which can range from clonal to highly recombinogenic. (
  • Rather, recombination rates seemingly reflect larger-scale patterns of viral genome organization, such that recombination may be a mechanistic by-product of the evolutionary pressures acting on other aspects of virus biology. (
  • First, we brie¯y review current knowledge of RNA virus recombination and describe new methods for detecting its occurrence using gene sequence data. (
  • We then discuss some of the evolutionary implications of virus recombination and some of the constraints that may shape the variety of RNA virus recombination. (
  • In some cases of RNA virus recombination, the donor sequence neatly replaces a homologous region of the acceptor sequence leaving its structure unchanged. (
  • This has been classified as `homologous recombination ' (Lai, 1992) since it involves not just homologous parental RNAs, but also crossovers at homologous sites. (
  • hybrid sequences resulting from aberrant homologous recombination (when similar viruses exchange sequence without maintaining strict alignment) and nonhomologous recombination (recombination between unrelated RNA sequences) are also commonly observed (Lai, 1992). (
  • 1997) presented evidence for a splicing-like, transesterication mechanism to explain the in vitro generation of recombinants between RNAs associated with Qb bacteriophage ± a possible exception to the copy±choice model of recombination in RNA viruses. (
  • There is now a fairly rich literature documenting recombination in RNA viruses. (
  • Dear virologists, It is often assumed that RNA viruses should have high mutation rates resulting from viral RNA polymerases which lack proofreading. (
  • i) How do the apparent mutation rates of DNA viruses compare to those of RNA viruses and ii) why do related viruses eg. (
  • HIV-1 and HTLV-1 have such different mutation rates if polymerase error is the only operating mechanism driving evolution of these viruses. (
  • RNA viruses, by virtue of their high mutation rates and large population sizes, from complex mutant distributions termed viral quasispecies. (
  • The two faces of mutation: extinction and adaptation in RNA viruses. (
  • Here we review experimental evidence for the effects of mutation, selection, and genetic drift on the adaptation and extinction of RNA viruses. (
  • DNA viruses have considerably lower mutation rates due to the proof-reading ability of DNA polymerases within the host cell. (
  • page needed] RNA viruses generally have very high mutation rates compared to DNA viruses, because viral RNA polymerases lack the proofreading ability of DNA polymerases. (
  • Mutation is the major cause of changes in the genetic code of the viruses. (
  • In RNA mutation is higher because RNA. (
  • 2. RNA mutation rate is higher than DNA mutation rate. (
  • No FHV RNAs accumulated in wt embryos injected with R1fs transcripts that contain a frame-shift mutation in the RdRP ORF ( Fig. 1 , lane 1). (
  • In HIV, for example, this high rate of mutation contributes to the rapid appearance of drug-resistant strains of the virus. (
  • However, the priming loop target site, which is suitable for non-nucleoside polymerase inhibitor design, shows significant differences in comparison with the dengue virus structures, including a tighter pocket and a modified local charge distribution. (
  • CDC DENV-1-4 Real-Time RT-PCR Assay for Detection and Serotype Identification of Dengue Virus. (
  • Other species include dengue virus, Tick-borne Encephalitis Virus, Yellow Fever Virus. (
  • The probable case definition criteria for Zika virus disease, based on serology, required Zika virus-specific IgM antibodies and no dengue virus-specific IgM antibodies detected in serum or cerebrospinal fluid. (
  • In preliminary studies that used referential RNA viruses , we attempted to determine the nucleic acid sequences of SARS coronavirus, mouse hepatitis virus, West Nile virus, Japanese encephalitis virus, and dengue virus type 2 in culture supernatants (10-100 [micro]L) by using the RDV method. (
  • Dengue virus isolates have been grown in the Igarashi clone C6/36 Aedes albopictus cells in amounts suitable for biochemical studies. (
  • Ebola virus (EBV) is a deadly virus that has resulted in a number of deaths during its outbreaks in Africa in 2014-2016 and 2018-2019. (
  • RNA viruses can be further classified according to the sense or polarity of their RNA into negative-sense and positive-sense , or ambisense RNA viruses. (
  • Ambisense RNA viruses transcribe genes from both the positive or negative strand. (
  • Ambisense RNA viruses resemble negative-sense RNA viruses, except they translate genes from their negative and positive strands. (
  • Disse enzymene savner korrekturlesing, og mutasjoner i genoma til RNA-virus blir slik lettere videreførte. (
  • Desse enzyma saknar korrekturlesing, og mutasjonar i genoma til RNA-virus vert slik lettare førte vidare. (
  • The two groups do not share a common dsRNA virus ancestor. (
  • In the Baltimore classification system, dsRNA viruses belong to Group III. (
  • The family Reoviridae is the largest and most diverse dsRNA virus family in terms of host range. (
  • Two clades of dsRNA viruses exist: the phylum Duplornaviricota and the class Duplopiviricetes, which is in the phylum Pisuviricota. (
  • Based on phylogenetic analysis of RdRp, the two clades do not share a common dsRNA ancestor but are instead separately descended from different positive-sense, single-stranded RNA viruses. (
  • Duplornaviricota contains most dsRNA viruses, including reoviruses, which infect a diverse range of eukaryotes, and cystoviruses, which are the only dsRNA viruses known to infect prokaryotes. (
  • The class Duplopiviricetes is the second clade of dsRNA viruses and is in the phylum Pisuviricota, which also contains positive-sense single-stranded RNA viruses. (
  • A distinguishing feature of the dsRNA viruses, irrespective of their family association, is their ability to carry out transcription of the dsRNA segments, under appropriate conditions, within the capsid. (
  • In turn, this dsRNA directs the formation of new viral RNA. (
  • The dsRNA pattern and the sequence information strongly indicate a virus associated with the mountain ash ringspot disease. (
  • RNAi could of course be used to regulate host cell gene expression, and in fact, it soon became clear that genomically encoded small RNAs very similar to siRNAs, called microRNAs (miRNAs), are present in the cells of all metazoan species. (
  • Because it has been shown that RNAi can be accomplished in cultured mammalian cells by introducing small interfering RNAs (siRNAs), much effort has been invested in exploiting this phenomenon for experimental and therapeutic means. (
  • Here, we tested the hypothesis that vectors based on feline immunodeficiency virus (FIV) could be used for coexpression of reporter constructs and RNAi expression cassettes. (
  • These include viruses highly pathogenic to humans, such as influenza virus, arenaviruses and filoviruses, that have not previously been reported in fish or amphibians. (
  • In a historic first, a group of CDC laboratory and bioinformatics scientists became the first to directly sequence an RNA genome. (
  • As the machine takes these measurements, it decodes the genetic sequence of the DNA or RNA strand. (
  • One capability of the nanopore sequencer is to sequence messenger RNA. (
  • It was this messenger RNA workflow that was modified to sequence influenza viral RNA. (
  • were able to get the machine to specifically target and sequence flu virus RNA. (
  • Now that Keller et al have managed to directly sequence RNA for the first time, the group hopes to find details of the influenza A virus' genome that are otherwise hidden and extremely difficult to detect. (
  • When sequenced, the redundant copies within each read are aligned to derive a consensus sequence of their initial RNA template. (
  • Unfortunately additional sequence data or virus isolations were not obtained in this study. (
  • Sequence-specific, single primer amplification and detection of PCR products for identification of hepatitis viruses. (
  • Quantitative nucleotide sequence relationships of mammalian RNA tumor viruses. (
  • Analyses based on primary nucleotide sequence homology and on secondary structures, characteristic to genotypes, revealed that the cDNA sequences belonged to bovine viral diarrhea virus (BVDV). (
  • Preliminary analyses of the 40 S RNA 5′ terminal sequence of DEN 3 virion RNA indicate that it has the composition of m7GpppAmpXp. (
  • Because viral evolution has not been able to tamper with this sequence, it is clear that it must be of vital importance to the viruses that have it, but no one knows exactly what its function is," said William Scott, an associate professor of chemistry and biochemistry at UC Santa Cruz. (
  • M. A. Nowak and R. M. May, Virus dynamics: Mathematical principles of Immunology and Virology ,, Oxford University Press , (2000). (
  • RNA modifications have generated much interest in the virology field, as recent works have shown that many viruses harbor these marks and modify cellular marks. (
  • A cell is infected with one (or more) virus particles. (
  • Arenaviridae are RNA viruses whose particles are spherical and have an average diameter of 110-130 nanometers. (
  • using vesicular stomatitis virus as a model it has been demonstrated that 'a many-trillionfold amplification of single RNA virus particles fails to overcome the Muller's ratchet effect (Duarte et al (1993) J. Virol. (
  • This finding reinforced the belief that RNA helped form virus particles. (
  • Sometimes the genome segments are separately packaged in virus particles. (
  • Perhaps transmission of these types of viruses by insect vectors facilitates the introduction of multiple virus particles into a cell. (
  • Virus particles are mostly isolated from the endoplasmic reticulum. (
  • The rate at which the fluorescence becomes brighter is related to the number of virus particles in the sample. (
  • No Zika virus RNA was detected in the accompanying serum/plasma sample. (
  • On the basis of previous small case studies reporting real time reverse-transcription polymerase chain reaction (RT-PCR) detection of Zika virus RNA in urine, saliva, and semen ( 2 - 6 ), the Florida Department of Health collected multiple specimen types from persons with suspected Zika virus disease. (
  • Of these, 65 (93%) tested positive for Zika virus RNA by RT-PCR. (
  • In fact, many virus outbreaks in humans are the result of animal-to-human transmission, as exemplified by the recent Ebola epidemic in West Africa 10 . (
  • Transmission electron micrograph of the ebola virus, hemorrhagic fever. (
  • The finding could be beneficial in understanding how these inhibitors react and potentially help develop a new generation of drugs to target viruses with high death rates, like HIV-1, Zika, Ebola and SARS-CoV2, the virus that causes COVID-19. (
  • The group of Negative-Stranded RNA Viruses (NSVs) includes many human pathogens, like the influenza, measles, mumps, respiratory syncytial or Ebola viruses, which produce frequent epidemics of disease and occasional, high mortality outbreaks by transmission from animal reservoirs. (
  • The protocol has enabled rapid deep sequencing of over 600 Lassa and Ebola virus samples-including collections from both blood and tissue isolates-and is broadly applicable to other microbial genomics studies. (
  • The exact reservoir of the ebola virus is not known, but different mammal groups are the source from which it is transferred to the human population. (
  • The role of different glycoproteins in the budding formation has helped a lot in understanding the physiology of the ebola virus. (
  • Recently, different groups have claimed the development of a successful vaccine for the ebola virus. (
  • The Ebola virus was first discovered back in 1976 when its breakout occurred simultaneously in South Sudan and in the area of Ebola River in Yambuku city of Democratic Republic of Congo ( Figure 1 ) [ 1 ]. (
  • The African originated species of Ebola virus fatality rate in humans is nearly 90% [ 2 ]. (
  • Ebola, Marburg, and Cueva virus are the three infectious viruses with a common ancestor of the family Filoviridae [ 2 ]. (
  • Examine Filoviridae viruses, like Ebola virus, Marburg virus and cuevavirus. (
  • By replacing a chemical group in RNA's ribose ring, Guo's team was able to make the RNA resistant to degradation, while retaining its ability to assemble into nanoparticles and form appropriate 3D structure and function. (
  • In contrast to simple binding of C5 and destabilization of the hairpin, C5-RIBOTAC's mode of action involved cleavage and degradation of SARS-CoV-2 RNA. (
  • FIV genes required for FIV virus production are indicated. (
  • Hepatitis C virus (HCV) triggers massive production of reactive oxygen species (ROS) and affects expression of genes encoding ROS-scavenging enzymes. (
  • But no virus has the thousands of genes required by even the simplest cells. (
  • This deletion probably spans part or all of the sequences of one or more genes in the nondefective sarcoma virus which are essential for cell transformation. (
  • A major focus of the project is understanding the many unusual mechanisms that RNA viruses use to express their genes. (
  • In another group of viruses called the potyviruses (the largest and most important group of plant RNA viruses) we discovered a new gene, termed pipo, that is absolutely essential for virus spread within infected plants. (
  • Wageningen University's scientists have identified RNA compounds that are preferentially being used during the initiation of the Influenza virus genome transcription. (
  • Part of the DNA-dependent RNA polymerase which catalyzes the transcription of viral DNA into RNA using the four ribonucleoside triphosphates as substrates. (
  • This method, often referred to as "reverse transcription polymerase chain reaction" (RT-PCR), works well for clinical purposes, such as identifying specific viruses from respiratory samples taken from sick patients. (
  • The foundation of this approach is the circularization of fragmented viral RNAs, which are then redundantly encoded into tandem repeats by 'rolling-circle' reverse transcription. (
  • In all these viruses, the enzymes required for endogenous transcription are thus part of the virion structure. (
  • CPV exhibits striking capsid stability and is fully capable of endogenous RNA transcription and processing. (
  • Once in the cell the single stranded RNA is able to go through transcription and translation. (
  • So that they simply don't have the needed pattern information transcription that dna has to be stable enough compared to dna virus? (
  • This observation is a direct demonstration that (-) strand DNA transcription begins at an internal position of the RNA genome, proceeds to the 5' end, reinitiates at the 3' end of the RNA, and copies the remainder of the viral genome. (
  • A comparison of reverse-transcription polymerase chain reaction (RT-PCR) test results for urine and serum specimens from 66 persons with Zika virus disease with both specimens collected on the same date indicated that approximately twice as many urine specimens (61) than serum specimens (31) tested positive. (
  • Electron microscopic heteroduplex analysis of avian RNA tumor viruses has been undertaken by using 35S viral RNA and long, complementary DNA synthesized in vitro. (
  • The 3 sequences cluster with Mobala virus (80% bootstrap support), an arenavirus discovered in Praomys sp. (
  • Keller said that messenger RNA has a tail end that is comprised of a sequences of "A's. (
  • Here, we review the tools utilized by positive-sense single-stranded (+ss) RNA plant viruses to initiate non-canonical translation, focusing on cis -acting sequences present in viral mRNAs. (
  • Sequences of flavivirus-related RNA viruses persist in DNA form integrated in the genome of Aedes mosquitoes. (
  • The genome sequences of RNA viruses evolve very rapidly so that there is considerable diversity between different isolates of a single virus species. (
  • By comparing the sequences of different virus isolates and computationally analysing the patterns of changes at different nucleotide positions (a technique known as ""comparative genomics""), we can predict novel functional elements and often gain extensive insight into their function. (
  • Finally, future research perspectives on the unusual translational strategies of +ssRNA viruses are discussed, including parallelisms between viral and host mRNAs mechanisms of translation, particularly for host mRNAs which are translated under stress conditions. (
  • Negative-sense ssRNA viruses (Group V) must have their genome copied by an RNA replicase to form positive-sense RNA. (
  • Most emerging infectious diseases of humans or domestic animals are zoonoses, and among emerging pathogens, RNA viruses are highly represented (1). (
  • To investigate the role of synanthropic small mammals as potential reservoirs of emerging pathogens in Ethiopia, we sampled rodent and shrew species in areas near human habitations and screened them for hantavirus and arenavirus RNA. (
  • RNA viruses are a large group of widespread and extremely prevalent pathogens capable of eliciting a broad spectrum of innate and adaptive immune responses. (
  • One of the three structural glycoproteins of classical swine fever virus (CSFV) is E0, a disulfide-bonded homodimer that induces virus-neutralizing antibodies and occurs in a virion-bound as well as a secreted form. (
  • When a complete virus particle ( virion ) comes in contact with a host cell, only the viral nucleic acid and, in some viruses, a few enzymes are injected into the host cell. (
  • In other viruses a reverse transcriptase contained in the virion transcribes the genetic message on the viral RNA into DNA, which is then replicated by the host cell. (
  • each virion can be transcribed to several positive-sense RNAs. (
  • Comparisons of the largest oligonucleotides derived by ribonuclease T1 digestion of these 40 S DEN virion RNA species indicate that there are few, if any, large oligonucleotides that are homologous between any two of the four dengue prototype strains. (
  • Circular resequencing (CirSeq) is a novel technique for efficient and highly accurate next-generation sequencing (NGS) of RNA virus populations. (
  • Sexual reproduction occurs in populations of the RNA virus φ6 when multiple bacteriophages coinfect the same host cell. (
  • Our findings indicate that high levels of coinfection exceed an optimum where sex may be beneficial to populations of φ6, and suggest that genetic conflicts can evolve in RNA viruses. (
  • Thus, as is known for other ecological systems, biodiversity and even cell killing of virus populations can be shaped by a tradeoff between competition and colonization. (
  • RNA libraries revealed single-stranded DNA (ssDNA) and RNA viral populations throughout the Baltic Sea, with ssDNA phage highly represented in Lake Torneträsk. (
  • Inferred virus-host relationships, community structures of ubiquitous ecologically relevant groups, and identification of transcriptionally active populations have been achieved with our Baltic Sea study. (
  • depict the special problems presented to the host by certain RNA viruses that are maintained and persist in human populations through avoidance or inhibition of apoptosis, innate immune response, and adaptive immune response. (
  • These findings establish a Drosophila model for studying the innate immunity against viruses in animals. (
  • However, it has been unclear if either pathway plays a role in Drosophila innate immunity against viruses ( 8 , 9 ). (
  • b) recovering the assembled infectious non-segmented negative-strand RNA virus. (
  • Detailed genetic information for RNA viruses from other classes of vertebrate is sorely needed if we are to fully understand long-term virus evolution. (
  • Tracking the evolution of RNA viruses. (
  • 6 sequenced RNA viruses present in various classes of vertebrate, and constructed trees of virus evolution. (
  • The authors found that RNA viruses co-diverged with their vertebrate hosts (black lines indicate virus evolution). (
  • This phylogenetic tree is a simplified schematic to exemplify RNA-virus evolution as a whole, and does not reflect precise dates or cross-species transmission events found by the authors. (
  • However, the researchers also show that some viruses can infect multiple hosts, indicating that, in addition to co-evolution, viruses have made jumps between species. (
  • In this paper we conduct the procedure of model order reduction for a reasonably simple model of RNA virus evolution reducing the original system of three integro-partial derivative equations to a single equation. (
  • Our results suggest a model for the evolution of virulence in viruses based on internal interactions within mutant spectra of viral quasispecies. (
  • Intriguingly, the fecal PMMV was infectious to host plants, suggesting that humans might act as a vehicle for the dissemination of certain plant viruses. (
  • Purified RNA of a negative-sense virus is not infectious by itself as it needs to be transcribed into positive-sense RNA. (
  • 2013 ), and in fact the host range of a given virus may be determined by its ability to efficiently translate viral mRNAs using host translation factors, as we have shown recently for a plant virus (Truniger et al. (
  • Deep sequencing of ClYVV RNA from infected plants endorses the slippage by viral RdRp. (