The phenomenon by which a temperate phage incorporates itself into the DNA of a bacterial host, establishing a kind of symbiotic relation between PROPHAGE and bacterium which results in the perpetuation of the prophage in all the descendants of the bacterium. Upon induction (VIRUS ACTIVATION) by various agents, such as ultraviolet radiation, the phage is released, which then becomes virulent and lyses the bacterium.
Viruses infecting insects, the largest family being BACULOVIRIDAE.
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).
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.
Viruses whose hosts are bacterial cells.
Genomes of temperate BACTERIOPHAGES integrated into the DNA of their bacterial host cell. The prophages can be duplicated for many cell generations until some stimulus induces its activation and virulence.
A genus of the family RETROVIRIDAE consisting of non-oncogenic retroviruses that produce multi-organ diseases characterized by long incubation periods and persistent infection. Lentiviruses are unique in that they contain open reading frames (ORFs) between the pol and env genes and in the 3' env region. Five serogroups are recognized, reflecting the mammalian hosts with which they are associated. HIV-1 is the type species.
Insect members of the superfamily Apoidea, found almost everywhere, particularly on flowers. About 3500 species occur in North America. They differ from most WASPS in that their young are fed honey and pollen rather than animal food.
Viruses whose host is Streptococcus.
Viruses whose genetic material is RNA.
A family of BACTERIOPHAGES and ARCHAEAL VIRUSES which are characterized by long, non-contractile tails.
The transfer of bacterial DNA by phages from an infected bacterium to another bacterium. This also refers to the transfer of genes into eukaryotic cells by viruses. This naturally occurring process is routinely employed as a GENE TRANSFER TECHNIQUE.
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.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
The introduction of functional (usually cloned) GENES into cells. A variety of techniques and naturally occurring processes are used for the gene transfer such as cell hybridization, LIPOSOMES or microcell-mediated gene transfer, ELECTROPORATION, chromosome-mediated gene transfer, TRANSFECTION, and GENETIC TRANSDUCTION. Gene transfer may result in genetically transformed cells and individual organisms.
Specific loci on both the bacterial DNA (attB) and the phage DNA (attP) which delineate the sites where recombination takes place between them, as the phage DNA becomes integrated (inserted) into the BACTERIAL DNA during LYSOGENY.
Progenitor cells from which all blood cells derive.
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.
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.
Proteins found in any species of virus.
Rupture of bacterial cells due to mechanical force, chemical action, or the lytic growth of BACTERIOPHAGES.
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.
Process of growing viruses in live animals, plants, or cultured cells.
A temperate inducible phage and type species of the genus lambda-like viruses, in the family SIPHOVIRIDAE. Its natural host is E. coli K12. Its VIRION contains linear double-stranded DNA with single-stranded 12-base 5' sticky ends. The DNA circularizes on infection.
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).
A broad category of viral proteins that play indirect roles in the biological processes and activities of viruses. Included here are proteins that either regulate the expression of viral genes or are involved in modifying host cell functions. Many of the proteins in this category serve multiple functions.
Viruses whose host is one or more Mycobacterium species. They include both temperate and virulent types.
A general term for diseases produced by viruses.
A species of POLYOMAVIRUS originally isolated from Rhesus monkey kidney tissue. It produces malignancy in human and newborn hamster kidney cell cultures.
Deoxyribonucleic acid that makes up the genetic material of viruses.
The assembly of VIRAL STRUCTURAL PROTEINS and nucleic acid (VIRAL DNA or VIRAL RNA) to form a VIRUS PARTICLE.
Viruses parasitic on plants higher than bacteria.
Viruses whose nucleic acid is DNA.
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 functional hereditary units of VIRUSES.
A family of BACTERIOPHAGES and ARCHAEAL VIRUSES which are characterized by complex contractile tails.
Viruses whose host is Salmonella. A frequently encountered Salmonella phage is BACTERIOPHAGE P22.
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.
The type species of MORBILLIVIRUS and the cause of the highly infectious human disease MEASLES, which affects mostly children.
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.
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.
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.
Viruses whose host is Staphylococcus.
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.
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 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.
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 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.
Viruses whose host is Escherichia coli.
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.
Any of the processes by which cytoplasmic factors influence the differential control of gene action in viruses.
Ribonucleic acid that makes up the genetic material of viruses.
Substances elaborated by viruses that have antigenic activity.
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.
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 relationships of groups of organisms as reflected by their genetic makeup.
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.
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.
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).
Viruses that produce tumors.
The complete genetic complement contained in a DNA or RNA molecule in a virus.
A CELL LINE derived from the kidney of the African green (vervet) monkey, (CERCOPITHECUS AETHIOPS) used primarily in virus replication studies and plaque assays.
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.
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.
The type species of RUBULAVIRUS that causes an acute infectious disease in humans, affecting mainly children. Transmission occurs by droplet infection.
The regulatory elements of an OPERON to which activators or repressors bind thereby effecting the transcription of GENES in the operon.
A species of RESPIROVIRUS also called hemadsorption virus 2 (HA2), which causes laryngotracheitis in humans, especially children.
Viruses which produce a mottled appearance of the leaves of plants.
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.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
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 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.
A species of ALPHAVIRUS isolated in central, eastern, and southern Africa.
Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Group of alpharetroviruses (ALPHARETROVIRUS) producing sarcomata and other tumors in chickens and other fowl and also in pigeons, ducks, and RATS.
A temperate coliphage, in the genus Mu-like viruses, family MYOVIRIDAE, composed of a linear, double-stranded molecule of DNA, which is able to insert itself randomly at any point on the host chromosome. It frequently causes a mutation by interrupting the continuity of the bacterial OPERON at the site of insertion.
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.
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).
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.
Viruses whose taxonomic relationships have not been established.
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.
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.
A phylum of bacteria consisting of the purple bacteria and their relatives which form a branch of the eubacterial tree. This group of predominantly gram-negative bacteria is classified based on homology of equivalent nucleotide sequences of 16S ribosomal RNA or by hybridization of ribosomal RNA or DNA with 16S and 23S ribosomal RNA.
Recombinases that insert exogenous DNA into the host genome. Examples include proteins encoded by the POL GENE of RETROVIRIDAE and also by temperate BACTERIOPHAGES, the best known being BACTERIOPHAGE LAMBDA.
A group of methylazirinopyrroloindolediones obtained from certain Streptomyces strains. They are very toxic antibiotics used as ANTINEOPLASTIC AGENTS in some solid tumors. PORFIROMYCIN and MITOMYCIN are the most useful members of the group.
The type species of ALPHARETROVIRUS producing latent or manifest lymphoid leukosis in fowl.
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 genus of gram-positive, coccoid bacteria whose organisms occur in pairs or chains. No endospores are produced. Many species exist as commensals or parasites on man or animals with some being highly pathogenic. A few species are saprophytes and occur in the natural environment.
The type species of ORBIVIRUS causing a serious disease in sheep, especially lambs. It may also infect wild ruminants and other domestic animals.
Virus diseases caused by the ORTHOMYXOVIRIDAE.
Established cell cultures that have the potential to propagate indefinitely.
The type species of RESPIROVIRUS in the subfamily PARAMYXOVIRINAE. It is the murine version of HUMAN PARAINFLUENZA VIRUS 1, distinguished by host range.
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.
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.
An antineoplastic antibiotic produced by Streptomyces caespitosus. It is one of the bi- or tri-functional ALKYLATING AGENTS causing cross-linking of DNA and inhibition of DNA synthesis.
A non-pathogenic species of LACTOCOCCUS found in DAIRY PRODUCTS and responsible for the souring of MILK and the production of LACTIC ACID.
The outer protein protective shell of a virus, which protects the viral nucleic acid.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
The type species of the FLAVIVIRUS genus. Principal vector transmission to humans is by AEDES spp. mosquitoes.
A genus of the family HERPESVIRIDAE, subfamily ALPHAHERPESVIRINAE, consisting of herpes simplex-like viruses. The type species is HERPESVIRUS 1, HUMAN.
The type species of TOBAMOVIRUS which causes mosaic disease of tobacco. Transmission occurs by mechanical inoculation.
Pneumovirus infections caused by the RESPIRATORY SYNCYTIAL VIRUSES. Humans and cattle are most affected but infections in goats and sheep have been reported.
The type species of LEPORIPOXVIRUS causing infectious myxomatosis, a severe generalized disease, in rabbits. Tumors are not always present.
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.
A species of ORTHOPOXVIRUS that is the etiologic agent of COWPOX. It is closely related to but antigenically different from VACCINIA VIRUS.
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 species of ORTHOPOXVIRUS causing infections in humans. No infections have been reported since 1977 and the virus is now believed to be virtually extinct.
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.
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.
Community of tiny aquatic PLANTS and ANIMALS, and photosynthetic BACTERIA, that are either free-floating or suspended in the water, with little or no power of locomotion. They are divided into PHYTOPLANKTON and ZOOPLANKTON.
A species of ALPHAVIRUS causing an acute dengue-like fever.
Degree of saltiness, which is largely the OSMOLAR CONCENTRATION of SODIUM CHLORIDE plus any other SALTS present. It is an ecological factor of considerable importance, influencing the types of organisms that live in an ENVIRONMENT.
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.
A phylum of bacteria comprised of three classes: Bacteroides, Flavobacteria, and Sphingobacteria.
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 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.
Biological properties, processes, and activities of VIRUSES.
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.
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).
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
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 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.
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 species of RESPIROVIRUS frequently isolated from small children with pharyngitis, bronchitis, and pneumonia.
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).
Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).
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 subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
The type species of APHTHOVIRUS, causing FOOT-AND-MOUTH DISEASE in cloven-hoofed animals. Several different serotypes exist.
Proteins that form the CAPSID of VIRUSES.
Specific hemagglutinin subtypes encoded by VIRUSES.
A species of ARTERIVIRUS causing reproductive and respiratory disease in pigs. The European strain is called Lelystad virus. Airborne transmission is common.
Any of the viruses that cause inflammation of the liver. They include both DNA and RNA viruses as well viruses from humans and animals.
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.
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.
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.
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.
Tumor-selective, replication competent VIRUSES that have antineoplastic effects. This is achieved by producing cytotoxicity-enhancing proteins and/or eliciting an antitumor immune response. They are genetically engineered so that they can replicate in CANCER cells but not in normal cells, and are used in ONCOLYTIC VIROTHERAPY.
The type species of PARAPOXVIRUS which causes a skin infection in natural hosts, usually young sheep. Humans may contract local skin lesions by contact. The virus apparently persists in soil.
A strain of PRIMATE T-LYMPHOTROPIC VIRUS 1 isolated from mature T4 cells in patients with T-lymphoproliferation malignancies. It causes adult T-cell leukemia (LEUKEMIA-LYMPHOMA, T-CELL, ACUTE, HTLV-I-ASSOCIATED), T-cell lymphoma (LYMPHOMA, T-CELL), and is involved in mycosis fungoides, SEZARY SYNDROME and tropical spastic paraparesis (PARAPARESIS, TROPICAL SPASTIC).
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.
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.
A positive-stranded RNA virus species in the genus HEPEVIRUS, causing enterically-transmitted non-A, non-B hepatitis (HEPATITIS E).
A strain of Murine leukemia virus (LEUKEMIA VIRUS, MURINE) producing leukemia of the reticulum-cell type with massive infiltration of liver, spleen, and bone marrow. It infects DBA/2 and Swiss mice.
The type species of BETARETROVIRUS commonly latent in mice. It causes mammary adenocarcinoma in a genetically susceptible strain of mice when the appropriate hormonal influences operate.
An enzyme that catalyzes the hydrolysis of alpha-2,3, alpha-2,6-, and alpha-2,8-glycosidic linkages (at a decreasing rate, respectively) of terminal sialic residues in oligosaccharides, glycoproteins, glycolipids, colominic acid, and synthetic substrate. (From Enzyme Nomenclature, 1992)
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.
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
Proteins found mainly in icosahedral DNA and RNA viruses. They consist of proteins directly associated with the nucleic acid inside the NUCLEOCAPSID.
Immunoglobulins produced in response to VIRAL ANTIGENS.
A group of replication-defective viruses, in the genus GAMMARETROVIRUS, which are capable of transforming cells, but which replicate and produce tumors only in the presence of Murine leukemia viruses (LEUKEMIA VIRUS, MURINE).
Viruses whose hosts are in the domain ARCHAEA.
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.
A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 7 and neuraminidase 7. The H7N7 subtype produced an epidemic in 2003 which was highly pathogenic among domestic birds (POULTRY). Some infections in humans were reported.
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.
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.
The type species of the genus AVIPOXVIRUS. It is the etiologic agent of FOWLPOX.
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 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).
The type species of DELTARETROVIRUS that causes a form of bovine lymphosarcoma (ENZOOTIC BOVINE LEUKOSIS) or persistent lymphocytosis.
Serologic tests in which a known quantity of antigen is added to the serum prior to the addition of a red cell suspension. Reaction result is expressed as the smallest amount of antigen which causes complete inhibition of hemagglutination.
A species of HENIPAVIRUS first identified in Australia in 1994 in HORSES and transmitted to humans. The natural host appears to be fruit bats (PTEROPUS).
The interactions between a host and a pathogen, usually resulting in disease.
The study of the structure, growth, function, genetics, and reproduction of viruses, and VIRUS DISEASES.
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.
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 LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.
A species in the genus Bornavirus, family BORNAVIRIDAE, causing a rare and usually fatal encephalitic disease in horses and other domestic animals and possibly deer. Its name derives from the city in Saxony where the condition was first described in 1894, but the disease occurs in Europe, N. Africa, and the Near East.
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 phenomenon in which infection by a first virus results in resistance of cells or tissues to infection by a second, unrelated virus.
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.
Human immunodeficiency virus. A non-taxonomic and historical term referring to any of two species, specifically HIV-1 and/or HIV-2. Prior to 1986, this was called human T-lymphotropic virus type III/lymphadenopathy-associated virus (HTLV-III/LAV). From 1986-1990, it was an official species called HIV. Since 1991, HIV was no longer considered an official species name; the two species were designated HIV-1 and HIV-2.
A species of MORBILLIVIRUS causing distemper in dogs, wolves, foxes, raccoons, and ferrets. Pinnipeds have also been known to contract Canine distemper virus from contact with domestic dogs.
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.
Proteins coded by the retroviral gag gene. The products are usually synthesized as protein precursors or POLYPROTEINS, which are then cleaved by viral proteases to yield the final products. Many of the final products are associated with the nucleoprotein core of the virion. gag is short for group-specific antigen.
The virus exits the host cell by budding. Acholeplasma species serve as the natural host. A productive infectious cycle begins ... Lysogeny involves integration into the host chromosome. "Viral Zone". ExPASy. Retrieved 15 June 2015. ICTV. "Virus Taxonomy: ... Mycoplasmatales virus-laidlawii 2 (L2) (tentative) Mycoplasmatales virus-laidlawii 3 (L3) (tentative) Mycoplasmatales virus- ... This family is poorly studied and little is known about these viruses. The family has one genus, Plasmavirus, which has one ...
The viruses then switch from lysis to lysogeny, so as to not deplete all available hosts. According to a team led by Alberto ... Cell Discovery. 5: 29-. doi:10.1038/s41421-019-0101-2. PMID 31149347. Dou C, Xiong J, Gu Y, Yin K, Wang J, Hu Y, Zhou D, Fu X, ... a negative regulator of lysogeny. Marina has also shown in the same system that the virus's arbitrium receptor interacts not ... "Communication between viruses guides lysis-lysogeny decisions". Nature. 541 (7638): 488-493. doi:10.1038/nature21049. ISSN 0028 ...
Viruses, for example, are obligate intracellular parasites and require a growth medium containing living cells. The most common ... growth media for microorganisms are nutrient broths (liquid nutrient medium) or lysogeny broth medium. Liquid media are often ... The two major types of growth media are those used for cell culture, which use specific cell types derived from plants or ... Selective growth media are also used in cell culture to ensure the survival or proliferation of cells with certain properties, ...
As the lysogenic cycle allows the host cell to continue to survive and reproduce, the virus is replicated in all of the cell's ... In contrast, the lysogenic cycle does not result in immediate lysing of the host cell. Those phages able to undergo lysogeny ... In this electron micrograph of bacteriophages attached to a bacterial cell, the viruses are the size and shape of coliphage T1. ... An altogether different phage type, the filamentous phages, make the host cell continually secrete new virus particles. ...
Depending on the virus, a variety of genetic changes can occur in the host cell. In the case of a lytic cycle virus, the cell ... This process is called lysogeny. As shown in Figure 2, a bacteriophage lands on a cell and pins itself to the cell. The phage ... The virus replicates using the host cell's machinery and then leaves the cell to infect additional cells via budding. There are ... and T-cell Leukemia virus type I. As many as 20% of human tumors are caused by viruses. Some such viruses that are commonly ...
As the lysogenic cycle allows the host cell to continue to survive and reproduce, the virus is replicated in all offspring of ... In contrast, the lysogenic cycle does not result in immediate lysing of the host cell. Those phages able to undergo lysogeny ... T7 phage T12 phage Viruses portal Virophage, viruses that infect other viruses Bacterivore CrAssphage DNA viruses Phage ecology ... An altogether different phage type, the filamentous phage, make the host cell continually secrete new virus particles. Released ...
Bacteriophages use a signaling peptides such as arbitrium to mediate the initiation of cell lysis and lysogeny in the host cell ... January 2017). "Communication between viruses guides lysis-lysogeny decisions". Nature. 541 (7638): 488-493. Bibcode:2017Natur. ... Fungi communicate in the phytobiome through chemical signaling to aid in sexual reproduction, sporulation, cell-to-cell ... doi:10.1016/j.cell.2017.04.025. PMID 28475891. Schaefer AL, Lappala CR, Morlen RP, Pelletier DA, Lu TY, Lankford PK, et al. ( ...
... whereas a lytic cycle is more immediate in that it results in many copies of the virus being created very quickly and the cell ... Lysogeny, or the lysogenic cycle, is one of two cycles of viral reproduction (the lytic cycle being the other). Lysogeny is ... When the bacterium reproduces, the prophage is also copied and is present in each of the daughter cells. The daughter cells can ... The genetic material of the bacteriophage, called a prophage, can be transmitted to daughter cells at each subsequent cell ...
... virus Ab22 Pseudomonas virus CHU Pseudomonas virus LUZ24 Pseudomonas virus PAA2 Pseudomonas virus PaP3 Pseudomonas virus PaP4 ... Entry into the host cell is achieved by adsorption into the host cell. DNA templated transcription is the method of ... In addition, their genome (around 45kb) does not encode obvious genes indicative of lysogeny. Genomes are linear, around 45kb ... "Virus Taxonomy: 2019 Release". International Committee on Taxonomy of Viruses. Retrieved 4 May 2020. ...
The virus will replicate and spread, generating regions of cell destruction known as plaques. For example, Vero cell or other ... due to partial resistance/lysogeny), or only reduce the rate of cell growth, give turbid plaques. Some partially lysogenic ... Assay Viral culture Virus Virus quantification Virology Finter, N. B (1969-10-01). "Dye Uptake Methods for Assessing Viral ... Non-viral spontaneous hole formation in cell culture (e.g. LLC-PK1, or the human gingival epithelial cell culture model, Gie- ...
Low temperature, starvation of the cells and high multiplicity of infection (MOI) are known to favor lysogeny (see later ... Enterobacteria phage λ (lambda phage, coliphage λ, officially Escherichia virus Lambda) is a bacterial virus, or bacteriophage ... This is followed by cell lysis, releasing the cell contents, including virions that have been assembled, into the environment. ... An important distinction here is that between the two decisions; lysogeny and lysis on infection, and continuing lysogeny or ...
... virus integration MeSH G04.185.515.880.930.500 - lysogeny MeSH G04.185.515.880.935 - virus latency MeSH G04.185.515.880.941 - ... cell proliferation MeSH G04.335.233.750.500 - cell division MeSH G04.335.233.750.500.220 - cell nucleus division MeSH G04.335. ... virus replication MeSH G04.185.515.880.941.940 - virus activation MeSH G04.185.515.880.941.950 - virus assembly MeSH G04.185. ... alpha-chain t-cell antigen receptor MeSH G04.610.626.325.211 - gene rearrangement, beta-chain t-cell antigen receptor MeSH ...
The propagation of the virions includes the attaching to a host cell (a bacterium, as Escherichia virus 186 is a bacteriophage ... The phage can enter two developmental lifecycles called the lytic cycle and lysogeny and knowledge into how the decision ... Escherichia virus 186 is a virus of the family Myoviridae, genus Eganvirus. As a member of the group I of the Baltimore ... To replicate its genetic content requires host cell DNA polymerases and, hence, the process is highly dependent on the cell ...
UV light stresses lysogenic bacteria, leading the phages to propagate and burst the host bacterial cells. In the case of T12, ... It is a proposed species of the family Siphoviridae in order Caudovirales (viruses with head-tail structure). It converts a ... Erythrogenic toxin A converts a harmless, non-virulent strain of Streptococcus pyogenes to a virulent strain through lysogeny, ... This mutant, the bacteriophage T12cp1, entered the lytic cycle, a life cycle in which the host cell is destroyed. In 1983, ...
Double-stranded RNA virus transcription is the method of transcription. The progeny viruses are released from the cell by lysis ... They did this by culturing various leaves in Lysogeny Broth and then plating the broth on lawns of Pseudomonas syringae pv ... virus phi6 Pseudomonas virus phi8 Pseudomonas virus phi12 Pseudomonas virus phi13 Pseudomonas virus phi2954 Pseudomonas virus ... Pseudomonas viruses φ7, φ8, φ9, φ10, φ11, φ12, and φ13 have been identified and named, but other cystovirus-like viruses have ...
On the contrary, lysogeny is favored when the host cell density is not high enough for maintenance of the phage density by ... Bacteriophage P2, scientific name Escherichia virus P2, is a temperate phage that infects E. coli. It is a tailed virus with a ... "ICTV Taxonomy history: Escherichia virus P2". International Committee on Taxonomy of Viruses. Retrieved 2019-01-14. Bowden, DW ... in the cell membrane and provide a pathway for endolysin escape to the cell wall. The nonessential genes, lysA and lysB, seem ...
"Communication between viruses guides lysis-lysogeny decisions". Nature. 541 (7638): 488-493. doi:10.1038/nature21049. ISSN 0028 ... Cell-to-cell communication in bacteria". Annual Review of Cell and Developmental Biology. 21: 319-346. doi:10.1146/annurev. ... When A. fischeri cells are free-living (or planktonic), the autoinducer is at low concentration, and, thus, cells do not show ... At low cell density, the molecules may just diffuse away. At high cell density, the local concentration of signaling molecules ...
As a result, many virus are made in the recipient cell, and lysis eventually occurs to release the new virus. Zygotic induction ... When the F− was lysogenic for λ, lysogeny was mapped to the gal locus. However, when the Hfr parent was lysogenic, lysogeny (i. ... In the donor cell, a repressor protein encoded by the prophage (viral DNA) keeps the viral genes turned off so that virus is ... Zygotic induction occurs when a bacterial cell carrying the silenced DNA of a bacterial virus in its chromosome transfers the ...
... to seek out new host cells to infect To infect a host cell, the virus must first inject its own nucleic acid into the cell ... The lysis-lysogeny decision is mainly influenced by the competition between Cro and CII, resulting in the determination of ... the virus hijacks the cell's replication and translation mechanisms, using them to make more viruses. The virus's nucleic acid ... The virus then releases its genetic material (either single- or double-stranded RNA or DNA) into the cell. In some viruses this ...
This is a last resort option- when the host cell has already been infected by the phage. This method is not ideal for the host ... The Bacteriophage Ecology Group (BEG): Home of Phage Ecology and Phage Evolutionary Biology ( The Virus Ecology ... CS1 maint: discouraged parameter (link) Barksdale L, Arden SB (1974). "Persisting bacteriophage infections, lysogeny, and phage ... Phages can acquire or use the enzyme from the host cell to protect their own DNA, or sometimes they will have proteins that ...
Viruses collected from these cells are then applied to the cells to be altered. The initial stages of these infections mimic ... Snyder L, Peters JE, Henkin TM, Champness W (2013). "Lysogeny: the λ Paradigm and the Role of Lysogenic Conversion in Bacterial ... Transduction is the process by which foreign DNA is introduced into a cell by a virus or viral vector. An example is the viral ... The new virus capsule that contains part bacterial DNA then infects another bacterial cell. When the bacterial DNA packaged ...
... chromosomally distinct episomes in cancer cells, where the viruses express oncogenes that promote cancer cell proliferation. In ... To clone longer lengths of DNA, lambda phage with lysogeny genes deleted, cosmids, bacterial artificial chromosomes, or yeast ... episomes remain physically separate from host cell chromosomes. Several cancer viruses, including Epstein-Barr virus and ... Daughter cells that retain a copy of the plasmid survive, while a daughter cell that fails to inherit the plasmid dies or ...
The viruses cannot move independently and must rely on currents, mixing, and host cells to transport them. Viruses cannot ... Ortmann, Alice C.; Lawrence, Janice E.; Suttle, Curtis A. (2002). "Lysogeny and lytic viral production during a bloom of the ... The tail binds the virus to the host cell and transfers viral DNA to the host cell upon infection. Based on morphological ... Virus Taxonomy Classification and Nomenclature of Viruses: Ninth Report of the International Committee on Taxonomy of Viruses. ...
Bacteriophages, known as phages, are a form of viruses. Phages attach to bacterial cells, and inject a viral genome into the ... The phage solutions are then tested to see which ones show growth suppression effects (lysogeny) or destruction (lysis) of the ... so one administered phage means one dead bacterial cell. Eventually these dead cells are consumed by the normal house-cleaning ... The bacterial cell causing the infection is unable to reproduce, and instead produces additional phages. Phages are very ...
... mammalian cell signalling, cell cycle, and cell fate decisions. The analyses of genetic network models, led Thomas to realise ... In this respect, Thomas demonstrated that the replication of the virus is directly blocked by the repressor ("Thomas-Bertani ... The intricacies of the regulatory network controlling the decision between lysis and lysogeny by bacteriophage lambda led ... This has major biological implications since, as first pointed out by Max Delbrück and amply confirmed since, cell ...
Paez-Espino D, Pavlopoulos GA, Ivanova NN, Kyrpides NC (August 2017). "Nontargeted virus sequence discovery pipeline and virus ... Rohwer, F (18 April 2003). "Global phage diversity". Cell. 113 (2): 141. doi:10.1016/s0092-8674(03)00276-9. PMID 12705861. ... "Metagenomic analysis of lysogeny in Tampa Bay: implications for prophage gene expression". PLOS ONE. 3 (9): e3263. doi:10.1371/ ... the largest interactive public virus database contained 265,000 metagenomic viral sequences and isolate viruses. This number ...
In the lytic cycle, the virus commandeers the cell's reproductive machinery. The cell may fill with new viruses until it lyses ... "A new perspective on lysogeny: prophages as active regulatory switches of bacteria". Nature Reviews Microbiology. 13 (10): 641- ... into the new host cell. This has the effect of causing the host cell to break apart. The DNA of the bacterial cell is silenced ... This mechanism eventually will lead to the release of the virus as the host cell splits open and the viral DNA is able to ...
The cloning vector may be DNA taken from a virus, the cell of a higher organism, or it may be the plasmid of a bacterium. The ... for example the genes for lysogeny since using phage λ as a cloning vector involves only the lytic cycle. There are two kinds ... In case of plants like Cauliflower mosaic virus , Tobacco mosaic virus and Gemini viruses have been used with limited success. ... The natural ability of viruses to adsorb to cells , introduce their DNA and replicate have made them ideal vehicles to transfer ...
It was unclear whether only one allele in each T-cell or 50% of T cells had 100% deletion in both alleles. Researchers have ... The virus, called a prophage in such a state, accomplishes this via integration and excision. The points where the integration ... Phages like the lambda phage use their site specific recombinases to integrate their DNA into the host genome during lysogeny. ... December 1996). "Subregion- and cell type-restricted gene knockout in mouse brain". Cell. 87 (7): 1317-26. doi:10.1016/s0092- ...
Viruses, for example, are obligate intracellular parasites and require a growth medium containing living cells. ... The most common growth media for microorganisms are nutrient broths (liquid nutrient medium) or LB medium (lysogeny broth). ... Cooper GM (2000). "Tools of Cell Biology". The cell: a molecular approach. Washington, D.C: ASM Press. ISBN 0-87893-106-6.. ... The two major types of growth media are those used for cell culture, which use specific cell types derived from plants or ...
... episomes remain physically separate from host cell chromosomes. Several cancer viruses, including Epstein-Barr virus and ... lambda phage with lysogeny genes deleted, cosmids, bacterial artificial chromosomes, or yeast artificial chromosomes are used. ... Daughter cells that retain a copy of the plasmid survive, while a daughter cell that fails to inherit the plasmid dies or ... The cells after transformation are exposed to the selective media, and only cells containing the plasmid may survive. In this ...
Unveiling the hidden theatre of microbes As cells, viruses and macromolecules represent the actors and stage set, so ... Metagenomic analysis of lysogeny in Tampa Bay: implications for prophage gene expression. PLoS One, 3(9), p.e3263. doi:10.1371/ ... Bassler, B.L. (2002) "Small talk: cell-to-cell communication in bacteria". Cell, 109(4): 421-424. doi:10.1016/S0092-8674(02) ... Cell, 178(4): 820-834. doi:10.1016/j.cell.2019.06.033. Schlaeppi, K. and Bulgarelli, D. (2015) "The plant microbiome at work". ...
"Intrinsically Disordered Segments Affect Protein Half-Life in the Cell and during Evolution". Cell Reports. 8 (6): 1832-1844. ... Many viruses also produce their proteins initially as a single polypeptide chain that were translated from a polycistronic mRNA ... tryptone in Lysogeny Broth. Proteases may be classified according to the catalytic group involved in its active site. Cysteine ... Proteins in cells are broken into amino acids. This intracellular degradation of protein serves multiple functions: It removes ...
Cells are typically rod-shaped, and are about 2.0 μm long and 0.25-1.0 μm in diameter, with a cell volume of 0.6-0.7 μm3. E. ... The process of transduction, which uses the bacterial virus called a bacteriophage, is where the spread of the gene encoding ... such as lysogeny broth, or any medium that contains glucose, ammonium phosphate monobasic, sodium chloride, magnesium sulfate, ... The bacterial cell cycle is divided into three stages. The B period occurs between the completion of cell division and the ...
Notable contributions include the discovery of the bacterial virus λ, the transfer of genes between bacteria by specialized ... which can exist either as an independent plasmid or integrate into the bacterial cell's genome. Lederberg's discovery of F ... did early research on the relationship between transduction and lambda phage lysogeny, discovered the E. coli F fertility ... ISBN 0-87969-350-9. Maugh II, Thomas H. (2006-11-30). "Esther Lederberg, 83; helped unlock mysteries of bacteria and viruses". ...
Virus-Cell Interactions. Cooperative Interaction of CI Protein Regulates Lysogeny of Lactobacillus casei by Bacteriophage A2. ... The cells were harvested, resuspended in 25 ml of buffer A (50 mM Tris-HCl [pH 7.5], 10 mM MgCl2, 1 mM dithiothreitol [DTT], ... It is likely, therefore, that this situation is reproduced in vivo when an A2 genome enters a new host cell. As a result of ... Under those conditions most of the CI, which accounted for about 2% of the total cell protein, was in the pellet of the crude ...
The virus exits the host cell by budding. Acholeplasma species serve as the natural host. A productive infectious cycle begins ... Lysogeny involves integration into the host chromosome. "Viral Zone". ExPASy. Retrieved 15 June 2015. ICTV. "Virus Taxonomy: ... Mycoplasmatales virus-laidlawii 2 (L2) (tentative) Mycoplasmatales virus-laidlawii 3 (L3) (tentative) Mycoplasmatales virus- ... This family is poorly studied and little is known about these viruses. The family has one genus, Plasmavirus, which has one ...
Purchase Viruses, Evolution and Cancer Basic Considerations - 1st Edition. Print Book & E-Book. ISBN 9780124297609, ... The Lysogeny Hypothesis Critically Revisited IV. The Mitogenic Effect of SV 40 and Polyoma Virus in Tissue Culture Cells V. ... The Cell Surface, Virus Modification, and Virus Transformation. I. Introduction II. Interactions of Viruses with the Cell ... Part I Host-Cell-Virus Relationships. Chapter 1. Host-Virus Relationship at the Embryonic Level. I. Introduction II. ...
Virus Integration. 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. ... Stem Cells In Wound Healing With Collagen Matrix as a Carrier. The purpose of the study is to use a collagen matrix embedded ... Cells on the luminal surface of the SYNOVIAL MEMBRANE. Type A synoviocytes are MACROPHAGES responsible for waste removal from ...
Until the 1930s the study of the obscure entities referred to as viruses was inseparable from the science of microbiology, a ... VirologyIntroductionVirology is a twentieth-century science that deals with viruses and viral diseases. ... When viruses replicate, the whole process from adsorption in the host cell membrane to the release of new viruses may take as ... When this phenomenon occurs in bacteriophage, it is called lysogeny.. By the end of the twentieth century, the growing threat ...
... forcing the DNA that is inside the virus through the cell wall and cell membrane. The entire virus protein coat remains outside ... producing infected daughter cells (see lysogeny). Lysis may eventually be triggered by environmental factors. Phages are used ... A virus infects a bacterial cell by first attaching to the bacterial cell wall by its tail. In coliphages the tail is a complex ... bacteriophage (băktēr´ēəfāj´), virus that infects bacteria and sometimes destroys them by lysis, or dissolution of the cell. ...
The viruses then switch from lysis to lysogeny, so as to not deplete all available hosts. According to a team led by Alberto ... Cell Discovery. 5: 29-. doi:10.1038/s41421-019-0101-2. PMID 31149347. Dou C, Xiong J, Gu Y, Yin K, Wang J, Hu Y, Zhou D, Fu X, ... a negative regulator of lysogeny. Marina has also shown in the same system that the viruss arbitrium receptor interacts not ... "Communication between viruses guides lysis-lysogeny decisions". Nature. 541 (7638): 488-493. doi:10.1038/nature21049. ISSN 0028 ...
The virus exits the host cell by budding. Acholeplasma species serve as the natural host.[2] ... After initial infection of the viral genome the virus may become latent within the host. Lysogeny involves integration into the ... Virus Taxonomy: 2014 Release. Retrieved 15 June 2015.. * ^ Büchen-Osmond, C. (Ed) (2003). 00.053. Plasmaviridae. In: ICTVdB- ... There are currently only one genus (Plasmavirus), and one species in this family: the type species Acholeplasma virus L2.[1][2] ...
The research shows that when multiple viruses infect a cell, the overall level of viral gene expression increases, which has a ... decisions about whether to kill host cells immediately after infection or enter a latent state to remain within the host cell. ... A new study suggests that bacteria-infecting viruses -- called phages -- can make collective ... dramatic nonlinear effect on gene networks that control cell fate. ...
Depending on the virus, a variety of genetic changes can occur in the host cell. In the case of a lytic cycle virus, the cell ... This process is called lysogeny. As shown in Figure 2, a bacteriophage lands on a cell and pins itself to the cell. The phage ... The virus replicates using the host cells machinery and then leaves the cell to infect additional cells via budding. There are ... and T-cell Leukemia virus type I. As many as 20% of human tumors are caused by viruses. Some such viruses that are commonly ...
Some viruses have a second life cycle called the lysogenic cycle. After the virus enters the host cell it can choose to insert ... its DNA directly into the hosts chromosome, a process called lysogeny.. The viral DNA is replicated along with the rest of the ... Genes in Viruses and Bacteria. Part I. Viruses. A virus is considered a noncellular organism consisting of DNA or RNA enclosed ... The virus remains dormant, producing only a repressor protein which prevents other viruses from attacking the cell until some ...
As the lysogenic cycle allows the host cell to continue to survive and reproduce, the virus is replicated in all of the cells ... In contrast, the lysogenic cycle does not result in immediate lysing of the host cell. Those phages able to undergo lysogeny ... In this electron micrograph of bacteriophages attached to a bacterial cell, the viruses are the size and shape of coliphage T1. ... An altogether different phage type, the filamentous phages, make the host cell continually secrete new virus particles. ...
... lysogeny), entering a state of dormancy. This anthropomorphic view may not be far from the truth. A recent study by Zohar Erez ... When a virus infects a cell, it has an important decision to make - whether to kill the host (lysis) or to integrate its DNA ... and colleagues in Israel, published in Nature, demonstrated that a small signalling peptide used mediates the lysis-lysogeny ... When a virus infects a cell, it has an important decision to make - whether to kill the host (lysis) or to integrate its DNA ...
Bacterial viruses (bacteriophages or phages) have DNA or RNA as genetic material. The two essential functions of genetic ... Lysogeny is a specific type of latent viral infection in which the phage genome replicates as a prophage in the bacterial cell ... Furthermore, the lysogenic cells are immune to superinfection by the virus which they harbor as a prophage. The physical state ... Prokaryotic cells (including bacteria) or eukaryotic cells (including yeast, animal or plant cells) can be used as recipients, ...
Biological networks enable molecules within cells, and even cells themselves, to communicate with each other and their ... Biological networks enable molecules within cells, and even cells themselves, to communicate with each other and their ... they receive information from the outside and inside of cells, integrate and interpret this information, and then activate a ... they receive information from the outside and inside of cells, integrate and interpret this information, and then activate a ...
Virus-Cell Interactions. ORF4 of the Temperate Archaeal Virus SNJ1 Governs the Lysis-Lysogeny Switch and Superinfection ... Virus-Cell Interactions. Patterns of Herpes Simplex Virus 1 Infection in Neural Progenitor Cells This study employed human ... Virus-Cell Interactions. Human Cytomegalovirus Utilizes Extracellular Vesicles To Enhance Virus Spread Human cytomegalovirus ( ... Virus-Cell Interactions. Cellular Vimentin Interacts with Foot-and-Mouth Disease Virus Nonstructural Protein 3A and Negatively ...
However, the virus must have had earlier access to a more common gene pool among the phages infecting low-G+C hosts, as ... Luria-Bertani medium was used for the incubation of E. coli cells at 37°C. Ampicillin (100 μg ml−1) was used for the selection ... Isolation and purification of bacteriophages.A total of 51 clostridial strains were screened for lysogeny by UV irradiation as ... The virus belongs to the Siphoviridae family of the tailed phages, the order Caudovirales. Its genome consists of a linear ...
The phage, then, is replicated each time the bacterial cell divides. In the lysogenic state, the bacteriophage can have ... Phage Models of Virus Emergence. *Host Density and Relative Fitness. *Virus Traps ... Bacteriophage Lysogeny Theres a great new post over at Microbiology Bytes about bacteriophage lysogeny.. Usually ... In lysogeny, the bacteriophage integrates its genome into that of its host. ...
Lysogeny Lysogeny results in the spread of the virus without killing the host cell.  Phage genes in the bacterial chromosome ... B- cells - Plasma cells - Memory cells . T- cells Helper T cells (effector T cells or Th cells) are the middlemen of the ... CD8+ cells destroy more CD4+ cells • CD4 cell loss means virus and infected cells no longer controlled • As CD4+ cells fall ... Memory T cells comprise two subtypes: central memory T cells (TCM cells) and effector memory T cells (TEM cells). Memory cells ...
From damaged genome to cell surface: transcriptome changes during bacterial cell death triggered by loss of a restriction- ... 1A). The lysogeny module, located downstream of the attP site, comprises a 382-aa integrase belonging to the Int family ( ... Virus-host interactions are regulated by complex coevolutionary dynamics. In Streptococcus pneumoniae, phase-variable type I ... C for 20 min to lyse the cells. A Maxwell 16 LEV simplyRNA cells kit (Promega) was then used along with a Maxwell 16 LEV ...
André Lwoff André Lwoff, French biologist who contributed to the understanding of lysogeny, in which a bacterial virus, or ... For this work, on which modern cell biology is partly based, Claude, his student George Palade, and Christian de…… ... The prize was given for research done on bacteriophages (viruses that infect bacteria). Hershey earned a doctorate…… ... of the 1991 Nobel Prize for Physiology or Medicine for research into basic cell function and for their development of the patch ...
He had deliberately infected them with a virus to test whether each ailing microbe soldiered on alone or communicated with its ... "This is a whole unexplored area." And the same goes for viruses that infect other cell types - including animal and human cells ... instead staying hidden in a sluggish state called lysogeny1. The viruses, it turns out, did not depend on bacterial cues to ... And two strains of influenza - one that excels at cell entry, the other at cell exit - grow better when maintained in cell ...
The composition of a virus is relatively simple, and its size is extremely small. It cannot even properly be called an organism ... The viruss genes are incorporated into the host cells genes, replicate as the cells genes replicate, and when the cell ... Closely related to lysogeny is the process known as transduction, whereby a virus carries bacterial genes from one host to ... Animal viruses enter host cells by a process called endocytosis. Plant viruses enter through wounds in the cells outer ...
wt.) genome of mycoplasma virus L2 in lysogenic Acholeplasma laidlawii cells was examined. For this study, DNAs were analysed ... L2 DNA was found to be integrated into the lysogenic host cell chromosome at a unique site in both viral and cellular DNA. The ... Integration and Lysogeny by an Enveloped Mycoplasma Virus * Kevin Dybvig and Jack Maniloff ... wt.) genome of mycoplasma virus L2 in lysogenic Acholeplasma laidlawii cells was examined. For this study, DNAs were analysed ...
Phospholipid bilayer that surrounds some viruses.. Glycoprotein. Proteins produced and secreted by cells infected with a virus ... Last name of the scientist that proposed lysogeny and gave the formal definition of a virus.. ... Protein that is on the outside of a virus that is responsible for attaching to the host cell for entry.. ... Viral fusion protein causes neighboring cells membranes to fuse.. Syncytia. Refers to the specific kinds of cells in a host ...
... host range and infection dynamics of marine viruses, as well as the subsequent effects of infection on both host cell ... Bacteriophages (that is, phages: viruses that infect bacteria) are highly abundant and are known to play critical roles in ... Viruses numerically dominate our oceans; however, we have only just begun to document the diversity, ... Weitz, J. S., Beckett, S. J., Brum, J. R., Cael, B. & Dushoff, J. Lysis, lysogeny and virus-microbe ratios. Nature 549, E1-E3 ( ...
Peptide antigens which are immunoreactive with sera from individuals infected with hepatitis C virus (HCV) are disclosed. ... POST-TRANSFUSION, NON-A, NON-B HEPATITIS VIRUS AND ANTIGENS. WO1990010060A1. 1990-09-07. NON-A, NON-B HEPATITIS HEPATOCYTE CELL ... which causes viral lysogeny at permissive temperatures, e.g., 32° C., and leads to viral lysis at elevated temperatures, e.g., ... Viral hepatitis resulting from a virus other than hepatitis A virus (HAV) and hepatitis B virus (HBV) has been referred to as ...
In general, most DNA viruses multiply in the host cells _____, while most RNA viruses multiply in the host cells _____. ... A common method for cultivating viruses in the lab is to use in vitro systems called _____ cultures. ... Two noncellular agents, smaller than viruses, are the infectious proteins called _____ and the infectious RNA strands called ... Lysogeny refers to. *. A. Altering the host range of a virus. *. B. ...
Lysogeny *Transduction Viruses. Properties: *They are obligate intracellular parasites. *Probably there are no cells in nature ... yellow fever virus *West Nile virus *Zika virus *dengue fever viruses *equine encephalitis viruses *hepatitis A ("infectious ... RNA Viruses *Negative-stranded RNA viruses *Positive-stranded RNA viruses *Double-stranded RNA viruses *Retroviruses *Latent ... SV40; a virus that infects primate cells and causes tumors in rodent cells. *Some bacteriophages *T2 and T4; from which much ...
Communication between viruses guides lysis-lysogeny decisions, by Zohar Erez et al., doi:10.1038/nature21049; and commentary: ... Cells are able to adapt ultra-rapidly to zero gravity. However, they were never exposed to it in the evolution of life on Earth ... Viruses... has a primer and links to ~1,000 examples of HGT, mostly by viruses.. 17 Feb 2017. ... A virus that infects bacteria listens to messages from its relatives when deciding how to attack its hosts. ...Phages caught ...
  • According to a team led by Alberto Marina at the Biomedical Institute of Valencia in Spain, also studying the Bacillus subtilis/ SPbeta phage system, arbitrium (AimP) binds to the AimX transcription factor AimR, and suppresses the activity of AimX, a negative regulator of lysogeny. (
  • The phage can then penetrate the cell membrane and inject the viral DNA into the host cell. (
  • To find out, the researchers modeled the complex gene regulatory dynamics of the lysis-lysogeny switch for lambda phage. (
  • A bacteriophage ( / b æ k ˈ t ɪər i oʊ f eɪ dʒ / ), also known informally as a phage ( / f eɪ dʒ / ), is a virus that infects and replicates within Bacteria and Archaea . (
  • Combined, it was deduced that as the peptide increased in concentration on phi3T infection it acted as a communication agent influencing the lysis-lysogeny choice of later generations of phage. (
  • 3 phage genes have been found that underpin the communication system: aimP, that encodes arbitrium, aimR, an intracellular peptide receptor that is a transcriptional activator of aimX, a negative regulator of lysogeny. (
  • These include DNA-packaging proteins, structural components, a dual lysis system, a putative lysogeny switch, and proteins that are involved in replication, recombination, and modification of phage DNA. (
  • Usually bacteriophages lyse their hosts following infection, however a few so-called "temperate" phage undergo lysogeny. (
  • The phage, then, is replicated each time the bacterial cell divides. (
  • During lysogeny, the phage had less of an effect on host gene regulation. (
  • Once within the cell, some of the bacteriophage genes (the "early" genes) are transcribed (by the host's RNA polymerase) and translated (by the host's ribosomes, tRNA, etc.) to produce enzymes that will make many copies of the phage DNA and will turn off (even destroy) the host's DNA. (
  • Furthermore, phages can influence ocean biochemistry through microbial cell lysis leading to the production of dissolved organic matter (DOM) and via auxiliary metabolic genes (AMGs) that alter cellular carbon, sulfur, and nitrogen metabolism of their hosts during the phage replication cycle ( 10 - 14 ). (
  • Thus, while the Δ mazEF cells die as a result of the lytic action of the phage, most of the mazEF + cells are killed by a different mechanism, apparently through the action of the chromosomal mazEF system itself. (
  • Thus, although mazEF action causes individual cells to die, upon phage growth this is generally beneficial to the bacterial culture because it causes P1 phage exclusion from the bacterial population. (
  • When the C/N/S journals question the applicability of phage research to "viruses," it means there are too few well-informed biologists out there to guide the media in the first place. (
  • Lytic phages are capable only of infections ending in bacterial cell death and release of new phage progeny (lytic life cycle), whilst temperate phages can either behave as lytic phages, or integrate into the genome of a bacterial host as a prophage (lysogenic life cycle) [ 1 ]. (
  • An infected cell is depicted at the top, in which injected phage DNA has rapidly circularized. (
  • Upon induction (VIRUS ACTIVATION) by various agents, such as ultraviolet radiation, the phage is released, which then becomes virulent and lyses the bacterium. (
  • A bacteriophage, or phage for short, is a virus that infects bacteria. (
  • The study identifies the AimP receptor, AimR, which binds to the phage DNA as a dimer in the absence of the arbitrium peptide, activating the transcription of the lysogeny repressor AimX. (
  • Although the mechanism whereby AimX negatively regulates lysogenic conversion remains to be elucidated, AimX mRNA expression is strongly repressed upon initial phage infection, its knockdown increases lysogeny and its ectopic expression can compensate for deletion of AimR in the induction of lysis. (
  • The model organism for studying lysogeny is the lambda phage . (
  • informally, phage / ˈ f eɪ dʒ / ) is a virus that infects and replicates within a bacterium . (
  • The lysis-lysogeny decision in the temperate coliphage λ is influenced by a number of phage proteins (CII and CIII) as well as host factors, viz. (
  • For example, phage virus infects only E. coll. (
  • Its example is phage virus. (
  • In lytic life cycle phage multiplies inside the host cell and the multiplication results in the lysis or disintegration of the host bacterium cell. (
  • The first step in infection of a host bacterial cell by a phage is adsorption. (
  • In lysogeny the viral DNA of the temperate phage, instead of taking over the function of the cell's genes, is incorporated into the host DNA and becomes a prophage in the bacterial chromosome, acting as a gene. (
  • Thereafter as the bacterial cell divides, phage DNA also replicates with it and is inherited by all the bacterial cells of following generations. (
  • Lysogeny requires λ repressor, the cI gene product, which shuts off transcription of the phage genome. (
  • Although both generalized transduction and specialized transduction can be regarded as the result of errors in phage production, transfer of genes between bacterial cells by phage is a reasonably common phenomenon. (
  • In transduction, DNA is accidentally moved from one bacterium to another by a virus or phage. (
  • Transduction is the process in which bacterial DNA is transferred from one bacterial cell to another by means of a phage particle. (
  • It has three forms: (a)Generalized transduction: It occurs in lytic cycle of phage virus. (
  • When the cell copies its DNA and divides, the integrated phage is copied too, so the daughter cells are infected. (
  • Alternatively, cholera can also grow in the environment, so the phage could infect a cell in the environment. (
  • Its a big world out there for a tiny phage and a tiny bacterial cell to meet each other. (
  • If the cell dies, the phage will not be able to replicate. (
  • What happens to the packaged DNA of a specialized transduced phage when it infects a new recipient cell? (
  • In a process known as lysogeny , a phage integrates its genome into a bacterial chromosome. (
  • The phage, now called a prophage, is then inherited by subsequent generations during cell replication. (
  • 10. The complex of claim 1, wherein the linear virus is fd or M13 phage. (
  • After the progeny phage particles reach a certain number, they cause the host to lyse, so they can be released and infect new host cells. (
  • This phage particle is known as a generalized transducing particle and is simply a carrier of genetic information from the original bacterium to another cell. (
  • Disambiguating bacteriophage pseudolysogeny: an historical analysis of lysogeny, pseudolysogeny, and the phage carrier state. (
  • This in itself confers two new properties on the cell, super infection immunity and the liability to revert to the lytic cycle with the production of new phage. (
  • If the cells are now doubly lysogenized by the addition of phage ε34 to cells that are already lysogenic for ε 15, the receptors are changed again so that neither phage can be adsorbed. (
  • In this particular case the presence of a prophage directs the cell to alter its surface receptors so that the cell becomes resistant to that phage (cf. the more normal super infection immunity). (
  • The system is also interesting in that such phage-coded alterations in the bacterial surface appear to be similar to the alterations in eukaryotic cell surface properties that occur after infection with integrated tumor viruses. (
  • a) Phage DNA is injected from the phage particle and either integrates in the chromosome (lysogeny) or enters the lytic cycle. (
  • d) Phage DNA is packaged in the capsid of the phage particle and cell lysis is effected to release progeny phage. (
  • The phage DNA is encapsulated in the capsid before the release of progeny phage from the cell by DNA‐packaging mechanisms. (
  • Lysis plaques of lambda phage on E. In response to stress, the activated prophage is excised from the DNA of the host cell by one of the newly expressed gene products and enters its lytic pathway. (
  • These repressive proteins are broken down when the host cell is under stress, resulting in the expression of the repressed phage genes. (
  • Holin A protein that creates a membrane spanning channel, and aids in the release of phage particles from an infected cell. (
  • Lysin A protein that degrades the cell wall and aids in the release of phage particles from an infected cell. (
  • Tail fiber The instrument of phage attachment to a host cell. (
  • Enterobacteria phage λ is a bacterial virus, or bacteriophage, that infects the bacterial species Lysis plaques of lambda phage on E. (
  • 1995. Significance of lysogeny to phage production and bacterial mortality in coastal waters of the Gulf of Mexico. (
  • Candidatus Pelagibacter" (SAR11) phage HTVC010P and Puniceispirillum phage HMO-2011 are considered the most abundant cultured marine viruses known to date. (
  • Lab Practicum 2 (AMG text pp ) September 4, 2001 Biology of Bacteriophage Lamda Lambda phage is a bacterial virus that infects E. coli, and depending on early events (and genetics), can either multiply within cells leading to cell lysis, or the viral DNA can integrate into the bacterial genome in a process called lysogeny. (
  • If lambda gene transcription is activated, then lytic infection occurs leading to phage release and infection of nearby E. coli cells. (
  • The bacterial debris (lysed cells) is removed by low speed centrifugation and then polyethylene glycol (PEG) is added to the supernatent and the phage are then pelleted by high speed ultracentrifugation. (
  • M13 Bacteriophage Biology M13 filamentous phage have a single strand genome that exists temporarily inside infected E.coli cells as a double strand plasmid. (
  • M13 phage are budded off of an infected cell and single strand DNA can be purified for use in DNA sequencing or in vitro mutagenesis. (
  • [1] Bacteriophages are ubiquitous viruses, found wherever bacteria exist. (
  • Bacterial viruses (bacteriophages or phages) have DNA or RNA as genetic material. (
  • The prize was given for research done on bacteriophages (viruses that infect bacteria). (
  • Viruses that infect bacteria - spiky lollipop-like creatures known as bacteriophages (or phages) - have surveillance mechanisms that bring them intel on whether to stay dormant or attack, depending on the availability of fresh victims . (
  • The viruses that infect bacteria are called bacteriophages. (
  • Bacteriophages attach to the surface of the bacterium and then penetrate the rigid cell wall, transmitting the viral nucleic acid into the host. (
  • In the case of bacteriophages, the new virions are usually released by bursting the host cell-a process called lysing, which kills the cell. (
  • Sometimes, however, bacteriophages form a stable association with the host cell. (
  • Bacteriophages (that is, phages: viruses that infect bacteria) are highly abundant and are known to play critical roles in bacterial mortality, biogeochemical cycling and horizontal gene transfer. (
  • The spatiotemporal distributions of the most abundant open-ocean bacteriophages that we report here provide new insight into viral temporal persistence, life history, and virus-host-environment interactions throughout the open-ocean water column. (
  • Some of the most common among these viruses in the open ocean are double-stranded DNA (dsDNA) bacteriophages (phages) that infect many abundant and biogeochemically important groups of bacterioplankton, such as Prochlorococcus , Synechococcus , and numerous heterotrophic bacterial species in common genera such as Roseobacter , Alteromonas , Pelagibacter , and Puniceispirillum ( 1 - 6 ). (
  • The nucleic acid of bacteriophages enters the host cell naked, leaving the capsid outside the cell. (
  • Many viruses have striking geometrically regular shapes, with helical structure as in tobacco mosaic virus, polyhedral (often icosahedral) symmetry as in herpes virus, or more complex mixtures of arrangements as in large viruses, such as the pox viruses and the larger bacterial viruses, or bacteriophages bacteriophage , virus that infects bacteria and sometimes destroys them by lysis, or dissolution of the cell. (
  • Certain viruses, such as bacteriophages, have complex protein tails. (
  • viruses that infect bacteria are referred to as bacteriophages (phages for short), and viruses that infect plants are called plant viruses . (
  • In some circumstances, a virus fails to reproduce itself and, instead, enters a latent state (called lysogeny in the case of bacteriophages), from which there is the potential for reactivation at a later time. (
  • Like other types of viruses, bacteriophages vary a lot in their shape and genetic material. (
  • viruses, particularly bacteriophages, are called temperate (or latent) because the infection does not immediately result in cell death. (
  • Evidence suggests that the majority of viruses in wetlands are bacteriophages, but despite their importance, studies on how viruses control the prokaryotic community and the concomitant impacts on ecosystem function (such as carbon cycling and greenhouse gas flux) in wetlands are rare. (
  • It was a conclusion far ahead of its time: not until the second half of the century would work on the same virus of tobacco mosaic, and on bacteriophages, by then supported by advances in methodology and technology, prove how right Beijerinck had been in his 'improbably wild' speculation. (
  • The viruses infecting bacteria are known as bacteriophages. (
  • Bacteriophages are the best understood viruses in terms of their gene structure and expression. (
  • Some bacteriophages (viruses that infect bacteria) can undergo a special kind of replication cycle called lysogeny. (
  • Bacteria and their viruses (known as bacteriophages , or phages), have a complicated relationship. (
  • Transmission electron micrograph of bacteriophages attached to a bacterial cell wall. (
  • Bacteriophages and animal viruses do NOT differ significantly in which one of the following steps? (
  • 1136 Bacteriophages can "listen in" on their host bacterium's quorum-sensing systems, shifting their lysis-lysogeny decisions based on host cell density. (
  • Olson, represented with a ribbon drawing (left) and as an elastic network (right), in which the lines represent the harmonic springs of the network connecting C ̨ atoms within 8A ̊ of each other process with other double-stranded DNA bacteriophages and with herpes virus [84]. (
  • After initial infection of the viral genome the virus may become latent within the host. (
  • The lysogenic pathway involves the virus inserting its genome into the bacterium's. (
  • The genome remains within the host cell until the virus is ready for replication. (
  • When a virus infects a cell, it has an important decision to make - whether to kill the host (lysis) or to integrate its DNA into the host genome (lysogeny), entering a state of dormancy. (
  • The second test involved deleting a transporter membrane protein from the bacterial genome that brings proteins of 3-20 amino acids into the cell. (
  • In lysogeny, the bacteriophage integrates its genome into that of its host. (
  • genome of mycoplasma virus L2 in lysogenic Acholeplasma laidlawii cells was examined. (
  • Their RNA (also single-stranded) is copied by reverse transcriptase into a DNA genome within the host cell. (
  • Viral marker gene distributions suggested that lysogeny was more prevalent at mesopelagic depths than in surface waters, consistent with prior prophage induction studies using mitomycin C. A total of 129 ALOHA viral genomes and genome fragments from 20 to 108 kbp were selected for further study, which represented the most abundant phages in the water column. (
  • A virus must attach to a living cell, be taken inside, manufacture its proteins and copy its genome, and find a way to escape the cell so that the virus can infect other cells. (
  • The genome sequence of this virus, determined using pyrosequencing, is 42,724 nucleotides in length with a mol% GC of 49.9 and is circularly permuted. (
  • A possible consequence of the presence of viral genome in a latent state is a new genotype for the cell. (
  • Additionally, the discovery of a cell from benthic group E ( Euryarchaeota ), a key member of the microbial community, containing a prophage in its genome supports the hypothesis that lysogeny is likely more pervasive than lytic infections in the deep biosphere. (
  • The viral genetic material remains dormant or is actually integrated into the genome of the host cell. (
  • In this process, the genome (the collection of genes in the nucleic acid core of a virus) of the bacteriophage stably integrates into the chromosome of the host bacterium and replicates in concert with it. (
  • During the lysogenic cycle, the virus genome is incorporated as prophage and a repressor prevents viral replication. (
  • Includes infection of a host cell, replication of the viral genome, and assembly of progeny virus particles. (
  • The new virions transport the viral genome to another host cell to carry out another round of infection. (
  • Widespread Genome Reorganization of an Obligate Virus Mutualist" [ html ], doi:10.1371/journal.pgen.1004660, 10(9): e1004660, PLoS Genet , 18 Sep 2014. (
  • Viral envelope fuse with plasma membrane of host and capsid and viral genome enters into the host cells. (
  • During lysogeny, the viral genome integrates into the host DNA, becoming a physical part of the chromosome. (
  • However, scientists estimate that approximately 8% of our genome can actually be traced back to viruses . (
  • Virus particles are structurally simple, often composed of just a nucleic acid genome protected by a protein coat called the capsid . (
  • The lysogenic cycle allows the genome of the virus to be replicated passively as the host cell's genome is replicated. (
  • Binding of the immunity repressor during lysogeny to the stoperator sites likely prevents transcription from the entirety of the genome other than those genes involved in the maintenance of lysogeny. (
  • Plasmaviridae is a family of bacteria-infecting viruses. (
  • A productive infectious cycle begins before a lysogenic cycle establishes the virus in the infected bacteria. (
  • bacteriophage (băktēr´ēəfāj´) , virus that infects bacteria and sometimes destroys them by lysis, or dissolution of the cell. (
  • Lysis can be readily observed in bacteria growing on a solid medium, where groups of lysed cells appear as clear areas, or plaques. (
  • They were studying communication in Bacillus subtilis bacteria - in particular, how bacteria infected with phages warn nearby uninfected bacteria about the presence of these viruses. (
  • Evolutionary biology portal Science portal Viruses portal Quorum sensing - the corresponding phenomenon in bacteria Dolgin, Elie (2019). (
  • A new study suggests that bacteria-infecting viruses - called phages - can make collective decisions about whether to kill host cells immediately after infection or enter a latent state to remain within the host cell. (
  • What has confounded the virology community for quite some time is the observation that the cell fate of a bacteria infected by a single virus can be dramatically different than that infected by two viruses," said Joshua Weitz, an assistant professor in the School of Biology at the Georgia Institute of Technology. (
  • One of the densest natural sources for phages and other viruses is seawater, where up to 9×10 8 virions per millilitre have been found in microbial mats at the surface, [3] and up to 70% of marine bacteria may be infected by phages. (
  • a virus that grew on and destroyed the bacteria. (
  • The long evolutionary battle between bacteria and viruses has produced the exquisite host-parasite specificity seen in their offensive and defensive mechanisms. (
  • Eventually the bacteria becomes nothing more than a bag full of viruses. (
  • Genetic information in bacteria and many viruses is encoded in DNA, but some viruses use RNA. (
  • But when he and his team at the Weizmann Institute of Science in Rehovot, Israel, looked into the contents of their flasks, they saw something completely unexpected: the bacteria were silent, and it was the viruses that were chattering away , passing notes to each other in a molecular language only they could understand. (
  • It seemed to work much like the communication system used by bacteria - quorum sensing - to share information about cell density and adjust the population accordingly. (
  • It cannot even properly be called an organism because it is unable to carry on life processes outside a living cell of an animal, plant, or bacteria. (
  • Unlike bacteria and other microorganisms, viruses remain dormant in body fluids. (
  • The release of new virions from plant and animal cells does not, however, always involve the bursting of the host cell as it does in bacteria. (
  • Munn, C. Viruses as pathogens of marine organisms-from bacteria to whales. (
  • Virions range in size from as small as the poliovirus shown above magnified some 450,000 times (courtesy of A. R. Taylor), which is 30 nm in diameter (about the size of a ribosome) to as large as Pithovirus sibericum an amoeba-infecting virus which, at 1,500 nm, is larger than many bacteria. (
  • Critical members of these communities are the viruses of marine bacteria, which can alter microbial metabolism and significantly influence their survival and productivity. (
  • Princeton University Professor Bonnie Bassler and graduate student Justin Silpe discovered a bacteria-killing virus (VP882) that can eavesdrop on bacterial conversations. (
  • In these images, E. coli bacteria harbor proteins from the eavesdropping virus. (
  • When the virus is in the "stay" mode (left), the bacteria grow and the red protein is spread throughout each cell. (
  • The idea that a virus is detecting a molecule that bacteria use for communication-that is brand-new," said Bassler, the Squibb Professor of Molecular Biology. (
  • VP882 has found a way to take the risk out of the decision: it listens for the bacteria to announce that they are in a crowd, upping the chances that when the virus kills, the released viruses immediately encounter new hosts. (
  • Viruses are not in the same kingdom as bacteria-in fact, they are not in any kingdom, because they are not technically alive. (
  • And viruses are even simpler than bacteria. (
  • The gist of the story is that Eric Wommack has discovered that many of the bacteria living near deep sea vents harbor viruses in their genomes. (
  • The article claims, "Marine phages - the viruses that parasitise bacteria and archaea in the sea - tend to infect their hosts, divide and burst them like balloons. (
  • Instead of hijacking bacteria to spawn offspring, these cell-splitting - or lysogenic - viruses insert their short genomes into the bacteria's own, endowing it with potentially useful genes. (
  • During training B. studied the mechanism of protection of bacteria from being absorbed by other cells. (
  • Binding of complement causes agglutination of red blood cells or bacteria, and the agglutination reaction can be detected with the naked eye. (
  • How do Viruses differ from bacteria? (
  • Viruses are tinier than bacteria. (
  • Unlike bacteria, viruses can't survive without a host. (
  • Do viruses attack bacteria? (
  • Lysogeny, type of life cycle that takes place when a bacteriophage infects certain types of bacteria. (
  • Also, the repressor produced by the prophage that prevents prophage genes from being expressed confers an immunity for the host bacteria from lytic infection by related viruses. (
  • Agar is a complex gelatinous carbohydrate, and is added to the LB broth (Lysogeny broth, Luria broth, Lennox broth, or Luria-Bertani medium), in order to form gel for bacteria to grow upon. (
  • When faced with making a decision at the group level, animals communicate with each other, so do bacteria, using quorum sensing pathways, and ̶ in an unexpectedly cool twist ̶ so do viruses! (
  • Changes can often involve the external membrane of the cell by making it impervious to other phages or even by increasing the pathogenic capability of the bacteria for a host. (
  • A bacteriophage (from bacteria and Greek φάγειν phagein to eat ) is any one of a number of viruses that infect bacteria. (
  • it can specifically target tumor tissue, it can destroy hypoxic tumor as well as normoxic tumor while minimizing damage to normal cells, and the bacteria can self-proliferate to reach an adequate density [ 1 , 2 ]. (
  • Virally caused mortality of bacteria estimated from published FVIC data of marine and freshwater systems and using the new conversion factors ranged from not detectable to 129%, thus confirming that viral infection is a significant and spatiotemporally variable cause of bacterial cell death. (
  • Ø For the exchange of genetic material in different species of bacteria and viruses the process of recombination is used. (
  • The vast majority of these viruses are obligate parasites of marine bacteria - the primary drivers of global carbon biogeochemistry [ 3 ]. (
  • After assembly of phages, the bacterial cell bursts, release new phages to infect other bacteria and begin the cycle over again. (
  • We demonstrate that rumen bacteria and viruses have differing responses and ecological drivers to dietary perturbation. (
  • Transduction is a mechanism of genetic recombination that occurs in bacteria where the incorporation of host cell DNA and the bacteriophage genetic material occurs, which results in the formation of recombinant DNA. (
  • 1. GENERALIZED TRANSDUCTION- Is the type of transduction in which a fragment of DNA from the degraded chromosome of an infected bacteria cell is accidentally incorporated into a … Like transformation and conjugation, transduction allows the movement of genetic information from a donor cell to a recipient. (
  • PRD1 is a bacteriphage, a virus that infects bacteria. (
  • Do all theses viruses share a common ancestor, which would have existed before the three domains of cellular life (eukarya, bacteria, archaea) diverged over 3 billion years ago? (
  • But bacteria have mechanisms to fight off viruses, so why wouldn't they stop this from happening in the first place? (
  • When growing populations of bacteria are confronted with bactericidal antibiotics, the vast majority of cells are killed, but subpopulations of genetically susceptible but phenotypically resistant bacteria survive. (
  • While it is convenient to consider genetically identical populations of bacteria as collections of physiologically homogeneous cells, they are commonly composed of phenotypically different subpopulations. (
  • Usually by some form of stochastic switch, during the course of growth or at stationary phase, bacteria of one phenotype produce cells of different phenotypes [1] - [6] . (
  • [0005] Recently, it has been proven that viruses are recognized as a useful tool in detecting a target analyte such as explosive substances, proteins, bacteria, viruses, spores, and toxic substances with high selectivity and sensitivity. (
  • Unnatural systems for production of R-type pyocins by bacterial cells generally regarded as safe ("GRAS") by regulatory authorities are described as are R-type pyocins produced by such GRAS bacteria. (
  • The relationship between these viruses and their host is called lysogeny, and bacteria that have been lysogenized are called lysogens . (
  • One may speculate, with Hayes, to what extent we unjustly incriminate bacteria in general for the sins of their viruses. (
  • Viruses infect nearly all forms of cellular life, including the bacteria, archaea and microeukaryotes that are the base of the ocean food web. (
  • There are two major types of growth media: those used for cell culture, which use specific cell types derived from plants or animals, and microbiological culture, which are used for growing microorganisms, such as bacteria or yeast. (
  • Phages are classified by the International Committee on Taxonomy of Viruses (ICTV) according to morphology and nucleic acid. (
  • The virus belongs to the Siphoviridae family of the tailed phages, the order Caudovirales . (
  • As the phages infect more cells, the message gets louder, signalling that uninfected hosts are becoming scarce. (
  • Phages then put a halt to lysis - the process of replicating and breaking out of their hosts - instead staying hidden in a sluggish state called lysogeny 1 . (
  • Phages can act as vectors for gene transfer and, by virtue of their ability to integrate in the bacterial chromosomes, they can permanently modify the properties of the host cell. (
  • When hosts are abundant, many phages undergo lytic cycles, increasing their population rapidly, but as host cell density declines, progeny phages are at risk of not finding prey to infect and must switch to lysogeny to avoid a collapse of the virus population. (
  • These are phages that destroy their host bacterial cell after infection. (
  • The host cell bursts to new phages which infect other bacterial cells. (
  • These are phages that do not harm and destroy the host bacterial cell. (
  • However, temperate phages may spontaneously become virulent at some subsequent generation and lyse the host cells, i. e, exhibit lysogenic cycle. (
  • Not all infections of bacterial cells by phages terminate in lysis. (
  • Like other temperate phages, P22 can follow either of two pathways following infection of a sensitive host cell it can grow lyrically, or form a lysogen. (
  • Some infectious phages invade bacterial cells, take over the host's molecular machinery, and use it to make hundreds of copies of themselves before killing the cell and moving on to the next host. (
  • Lysis and the interaction between free phages and infected cells. (
  • As shown in Figure 2, a bacteriophage lands on a cell and pins itself to the cell. (
  • The Israeli team's discovery of a small signaling peptide was made in phi3T, a bacteriophage virus that infects Bacillus subtilis. (
  • There's a great new post over at Microbiology Bytes about bacteriophage lysogeny. (
  • Engelberg-Kulka H, Reches M, Narasimhan S, Schoulaker-Schwarz R, Klemes Y, Aizenman E, Glaser G (1998) rexB of bacteriophage lambda is an anti-cell death gene. (
  • After it infects host E. coli cells, bacteriophage λ follows either of two fates, lytic or lysogenic. (
  • Like all viruses , the bacteriophage are composed of a nucleic acid core surrounded by a protein coat, the capsid made up of sub-units, the capsomeres. (
  • In the other phase (termed the lysogenic phase), the bacteriophage inserts itself into the bacterial chromosome where it resides until a stimulus (for example, irradiation with ultraviolet light) causes the virus to enter the lytic phase. (
  • c) further comprising providing to said cell a modified bacteriophage lambda integrase Int , wherein said modified Int is Int-h or Int-h/218 , which induces sequence specific recombination through said attB and attP or attR and attL sequences . (
  • 2 most important Types of Cycle that occurs in Bacteriophage Virus are Lytic-cycle and Lysogenic Cycle. (
  • The bacterial virus lambda (λ) is a temperate bacteriophage that can lysogenize host Escherichia coli (E. coli) cells. (
  • Lysis of lysis inhibited bacteriophage T4-infected cells. (
  • This allows a detailed analysis of the chemical structure of the cell surface components that make up the O-antigens and bacteriophage receptors of the cell. (
  • We found that the vast majority of viruses from the human gut were novel species of bacteriophage, and that only 1 of these 12 individuals contained a known eukaryotic DNA virus. (
  • Biochemically, many viruses inhibit the synthesis of host DNA, RNA, proteins directly or even interfere with protein-protein, DNA-protein, RNA-protein interactions at the subcellular level. (
  • Our study suggests that viruses can collectively decide whether or not to kill a host, and that individual viruses 'talk' to each other as a result of interactions between viral genomes and viral proteins they direct the infected host to produce. (
  • Once a virus gets the upper hand it commandeers the bacteria's own RNA polymerase to make viral proteins and enzymes some of which chop up the bacteria's DNA for the nucleotides necessary to make viral DNA. (
  • The interplay of these three proteins effectively switches the phage's choice from lysis to lysogeny. (
  • Viruses hijack cellular proteins, termed viral receptors, to assist their entry into host cells. (
  • some viruses also have an outer envelope composed of fatty materials and proteins. (
  • Proteins produced and secreted by cells infected with a virus which stimulate production of antiviral proteins in neighboring cells. (
  • They encode those proteins needed for viral reproduction that the host cell will not supply . (
  • Often, one or more proteins (enzymes) needed to start the process of reproduction within the host cell. (
  • The proteins of the capsid inject the DNA core into the cell (b) . (
  • A virus attaches to a specific receptor site on the host cell membrane through attachment proteins in the capsid or via glycoproteins embedded in the viral envelope. (
  • The nucleic acid specifies information for the synthesis of from a few to 50 different proteins, depending on the type of virus. (
  • A free virus particle may be thought of as a packaging device by which viral genetic material can be introduced into appropriate host cells, which the virus can recognize by means of proteins on its outermost surface. (
  • Report Scope: The scope of this study encompasses an investigation of the markets cell and gene therapy tools such as GMP proteins, media, cell separation and activation reagents, viral and non-viral, cytokine release syndrome monitoring products, GMP antibodies, leukapheresis instrumentation, immunoassays (multiplex and. (
  • The simplest viruses contain only enough RNA or DNA to encode four proteins. (
  • Other factors such as λCIII and the host hfl proteins that influence the lysis-lysogeny switching affect the stability of CII in one way or the other. (
  • Similarly, some proteins are present on surface of the virus. (
  • The virion attaches itself to host cell through ionic bonds or at more or less specific receptor sites which interact with specific proteins in the capsids or the virion. (
  • Because the genes encoding the proteins that mediated the lysogenic life cycle are unnecessary for the lytic phase, the virus was an ideal candidate for use as a cloning vector. (
  • A great example of this is the structure of capsid proteins from three very different viruses. (
  • But it turns out that the capsid proteins of these three viruses are actually quite similar. (
  • We sometimes are able to generate antibodies (immune system proteins) that bind to and cover up some of the proteins on the outermost portion of a virus while it is in the bloodstream. (
  • This disclosure also relates to R-type pyocins wherein the tail fibers are modified to include globular proteins, which proteins can bind and degrade cell surface structures, such as polysaccharides. (
  • This thesis includes structural biochemical work in combination with mutational and functional studies of proteins from both human and virus. (
  • Pneumococcal cells secrete a protein competence factor that induces many of thecells of a culture to synthesize special proteins necessary for transformation, including an autolysin that exposes a cell membrane DNA-binding protein. (
  • A virus infects a bacterial cell by first attaching to the bacterial cell wall by its tail. (
  • a virus that infects primate cells and causes tumors in rodent cells. (
  • However, the damage to the cells that the virus infects may make it impossible for the cells to function normally, even though the cells remain alive for a period of time. (
  • A bacterial virus infects the cell by attaching fibers of its protein tail to a specific receptor site on the bacterial cell wall and then injecting the nucleic acid into the host, leaving the empty capsid outside. (
  • Infects T cells. (
  • However, when λ infects ΔhflKC cells, turbid plaques are produced, indicating stabilization of CII under these conditions. (
  • Each type of virus infects only a limited range of hosts. (
  • The first, the lytic phase, displays conventional viral behavior, wherein the virus infects the bacterial cell, replicates exponentially and eventually lyses the cell with release of the multiplied viral particles. (
  • STIV (Sulfolobus turreted icosahedral virus) infects Sulfolobus, an archaea that lives in geothermal hotsprings in Yellowstone National Park. (
  • In hfla strains of E. coli, expression of the lambda cii gene is elevated, resulting in transcriptional induction of the lambda ci repressor gene which promotes lysogeny. (
  • Two temperate viruses, φ3626 and φ8533, have been isolated from lysogenic Clostridium perfringens strains. (
  • What Is The Benefit For A Virus To Be A Temperate Or Lysogenic Virus? (
  • What are temperate viruses? (
  • In this instance genetic material of the temperate viruses attaches itself to a bacterial chromosome in a different manner. (
  • A large proportion of viral contigs have markers of temperate lifestyle, indicating that there is a significant role of lysogeny in the gut microbiome. (
  • At the beginning of the twentieth century, the term "virus" referred to infectious agents that could not be seen under the microscope, trapped by filters, or grown in laboratory cultures. (
  • After the establishment of germ theory in the late nineteenth century, virus generally referred to unidentifiable entities with infectious properties. (
  • The infectious agents now known as viruses originally attracted attention because of the diseases they produce in their animal and plant hosts. (
  • In productive infections, additional infectious viruses are produced. (
  • Abortive infections do not produce infectious viruses. (
  • The final stop in the viral life cycle is to lyse (rupture) the membrane surrounding the host cell releasing hundreds of new infectious particles. (
  • Prophages can convert to infectious viruses through a process known as induction, which is relevant to the spread of bacterial virulence genes. (
  • Two classes of infectious agents exist that are structurally simpler than viruses, namely, viroids and prions. (
  • The entire infectious virus particle, called a virion, consists of the nucleic acid and an outer shell of protein. (
  • Viruses are tiny infectious agents that rely on living cells to multiply. (
  • In the late 1890s, and into the turn of the century, what came to be labelled 'filterable viruses' or 'invisible viruses' (throughout the nineteenth century 'virus', in France in particular, had been used as a blanket term for the 'new' infectious agents) were identified in increasing numbers. (
  • A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. (
  • Viruses are not cells but non-living, infectious particles. (
  • Hodgkin's lymphoma motives: Infectious mononucleosis - contamination with the epstein-Barr virus. (
  • Significance of photoreactivation for maintaining high concentrations of infectious viruses in the sea. (
  • This activates the P RM promoter, which is divergent from P R , thereby activating the transcription of genes responsible for the maintenance of lysogeny ( 13 , 17 , 19 , 21 , 27 ). (
  • The genes required for lytic development show an opposite orientation and arrangement compared to the lysogeny control region. (
  • Scientists first spied viruses mingling in the 1940s, when separate experiments by biophysicist Max Delbrück and bacteriologist Alfred Hershey showed that two viral particles could simultaneously invade the same cell and swap genes. (
  • The nucleic-acid core is the essential part of the virus-it carries the virus's genes. (
  • Once inside the host cell, the virus's genes usually direct the cell's production of new viral protein and nucleic acid. (
  • The virus's genes are incorporated into the host cell's genes, replicate as the cell's genes replicate, and when the cell divides, the viral genes are passed on to the two new cells. (
  • Its genes, however, are passed on to each new generation of cells that stem from the original host cell. (
  • These cells remain healthy and continue to grow unless, as happens occasionally, something triggers the latent viral genes to become active. (
  • When this happens, the normal cycle of viral infection results: the viral genes direct viral replication, the host cell bursts, and the new virions are released. (
  • Closely related to lysogeny is the process known as transduction, whereby a virus carries bacterial genes from one host to another. (
  • A virus is a set of genes, composed of either DNA or RNA, packaged in a protein- containing coat called a capsid . (
  • Phylogenetic analysis of the identified viral genes indicated that the viruses were most similar to large inducible lysogenic myoviruses. (
  • Mutations in the cI, cII and cIII genes of λ [ 10 ] enhances the lytic frequency (leading to clear plaque formation, hence the names) and therefore the products of these genes were thought to be responsible for the establishment of lysogeny. (
  • Genes in normal cells that encode products that stop uncontrolled cell proliferarion. (
  • The expression of viral genes is regulated in such a way that the lysis of the host cells is caused. (
  • The cell growth impairment is mediated by two ICE clc located genes, parA and shi , but the mechanistic and dynamic details of this process are unknown. (
  • Moreover, analysis of virally encoded auxiliary metabolic genes (AMGs) indicates rumen viruses have glycosidic hydrolases to potentially augment the breakdown of complex carbohydrates to increase energy production. (
  • Other studies have found that viral genes may help embryonic stem cells to differentiate into the various tissues that make up a functional human. (
  • Furthermore, viruses in marine environments and hot springs move genes between organisms in all three domains of life. (
  • It is important to understand that host genes are packaged in the virus particle because of errors made during the virus's life cycle. (
  • The virion containing these genes then transfers them to a recipient cell. (
  • Transduction is totally medi-ated by virus genes, and conjugation, by plasmid genes. (
  • The protein capsid protects the nucleic acid and may contain molecules that enable the virus to enter the host cell-that is, the living cell infected by the virus. (
  • Typically the protein coat, or capsid, of an individual virus particle, or virion, is composed of multiple copies of one or several types of protein subunits, or capsomeres. (
  • In viruses with a membrane envelope the nucleocapsid (capsid plus nucleic acid) enters the cell cytoplasm by a process in which the viral envelope merges with a host cell membrane, often the membrane delimiting an endocytic structure (see endocytosis endocytosis , in biology, process by which substances are taken into the cell. (
  • Some pieces of DNA also enter into capsid of virus. (
  • Enveloped viruses have a layer of lipids surrounding their capsid. (
  • Importantly, for lysogenic conversion to occur, it is not necessary that the prophage remains functional as a virus that is capable of prophage induction or lytic growth. (
  • A less risky approach might be to limit virulence and allow prophage infected cells to survive. (
  • Now if the prophage finds itself in cells that are no longer growing, there may be an advantage to getting out and finding "happy" hosts. (
  • In the span of a few days, or even hours, the prophage-carrying cells may begin to dominate the population. (
  • The presence of prophage DNA in a cell constitutes a genetic alteration to the cell. (
  • Define plaque lysogeny and prophage stage. (
  • Crucial in the maintenance of lysogeny and prophage stability. (
  • Answer to Define plaque, lysogeny, and prophage. (
  • Lysogeny involves integration into the host chromosome. (
  • After the virus enters the host cell it can choose to insert its DNA directly into the host's chromosome, a process called lysogeny. (
  • L2 DNA was found to be integrated into the lysogenic host cell chromosome at a unique site in both viral and cellular DNA. (
  • In some viruses after infection of the host cells viral particles get integrated with the host chromosome (DNA) and replicate along with it (lysogeny). (
  • ICEs are usually retained within the bacterial chromosome, but can be excised and transferred from a donor to a new recipient cell, even of another species. (
  • Sorek has suggested that since human viruses like HIV and herpes simplex can cause active and latent infections, they might be using an arbitrium-like system to communicate. (
  • In this case, that analogue could be used to suppress infections by making the viruses completely latent. (
  • There are three types of persistent infections, latent, chronic and slow, in which the virus stays inside the host cell for prolonged periods of time. (
  • Changes in viral gene expression can have a dramatic nonlinear effect on gene networks that control whether viruses burst out of the host cell or enter a latent state. (
  • Some determinants of bacterial virulence and some malignancies of animal cells are examples of the genetic effects of latent viruses. (
  • The genus Flavivirus includes major human pathogens, as well as animal-infecting viruses with zoonotic potential. (
  • The entire virus protein coat remains outside the bacterium. (
  • In fact, the largest virus is smaller than the smallest bacterium. (
  • Transduction (genetics) - Transduction Transduction is the process by which DNA is transferred from one bacterium to another by a virus. (
  • It breaks the cell wall and cell membrane of bacterium. (
  • The progeny is released to attack new bacterium cells. (
  • The viral DNA takes control of the cell metabolism and directs the bacterium for production of viral enzymes using ribosomes of host. (
  • In lysogeny, the bacterium metabolizes and reproduces normally, the viral DNA is transmitted to each daughter cell through all successive generations. (
  • Occasionally this bacterium will spontaneously start making viral components and these components will be assembled into mature virus particles. (
  • In these cases, lysogeny not only gives the cell superinfection immunity, it also actively influences the virulence of the bacterium for man. (
  • The research, published in the September 15 issue of the Biophysical Journal, shows that when multiple viruses infect a cell, this increases the number of viral genomes and therefore the overall level of viral gene expression. (
  • Gene cloning is the incorporation of a foreign gene into a vector to produce a recombinant DNA molecule that replicates and expresses the foreign gene in a recipient cell. (
  • We identified 172,385 different viral gene families and 129 unique virus genotypes in this open-ocean setting. (
  • Also, metabolic and host cell immune response differences seen in different cell types based on differential gene expression are a likely factor in which cells a virus may target for replication. (
  • Vertical gene transfer is the transfer of genetic material during cell division. (
  • 11. The complex of claim 1, wherein biotin or streptavidin is bound to a protein located at one end of the virus, or the virus is gene-manipulated to express a fusion protein of biotin or streptavidin and a virus protein. (
  • Phylogeny of large double-stranded DNA viruses which infect microalgae, as inferred from DNA polymerase gene sequences. (
  • Insertional cloning into the ci gene of the lambda-gt10 cdna cloning vector (DNA inserts of ~1-5 kb) can be selected in hfl (high frequency of lysogeny) mutant strains of E. coli. (
  • These components are then assembled into new, complete, infective virus particles called virions, which are then discharged from the host cell to infect other cells. (
  • Outside the cell, they consist of particles called virions . (
  • Later studies of virus crystals established that the crystals were composed of individual virus particles, or virions. (
  • Isolated viruses are only protein-coated particles. (
  • Thus, viruses use the host machinery such as enzymes, ribosomes and other components to replicate, to form the coat and to form more virus particles. (
  • Thereafter many virus particles (lytic) are liberated which can infect new host cells to repeat the lytic-cycle. (
  • An independent synthesis of viral components occurs within the cell followed by an assembly of those components into complete virus particles. (
  • After a well defined period the bacterial cell bursts and releases the newly formed virus particles. (
  • The liberated virus particles again infect the bacterial cells and the lytic cycle is repeated. (
  • VSV particles are rod-shaped (hence the name rhabdo, from the Greek for rod) enveloped viruses of approximate dimensions 70 X 180 nm (Fig. 1). (
  • Each plaque contains about 1 million virus particles derived from a single infection event - the viral particles in a single plaque are therefore clonally related (same DNA sequence). (
  • The virion attaches to the surface of the host cell - usually binding to a specific cell surface molecule that accounts for the specificity of the infection. (
  • A virus that is outside of a host cell is known as a virion. (
  • In some cases, complete virion enters into the host like AIDS virus. (
  • The resulting virion often injects the DNA into another bacterial cell but cannot initiate a lytic cycle. (
  • The viruses then switch from lysis to lysogeny, so as to not deplete all available hosts. (
  • So, when there are lots of phi3T, there will be a high concentration of arbitrium triggering this switch to lysogeny. (
  • In this state, known as lysogeny, the information contained in the viral nucleic acid is not expressed. (
  • In some cases, an entirely different relationship, known as lysogeny, meaning having potential for lysis, may develop between the virus and its bacterial host. (
  • When the lytic pathway is selected, the virus utilizes bacterial resources to replicate and then destroys the host cell, releasing new viruses that can infect other cells. (
  • The newly formed viruses infect other cells and in this way a new cycle started. (
  • They were deciding together when to lie low in the host cell and when to replicate and burst out, in search of new victims. (
  • Cells that a virus may use to replicate are called permissive . (
  • The permissive cell must make the substances that the virus needs or the virus will not be able to replicate there. (
  • A virus must use cell processes to replicate. (
  • in the other stage, however, viruses enter living plant, animal, or bacterial cells and make use of the host cell's chemical energy and its protein- and nucleic acid-synthesizing ability to replicate themselves. (
  • Even though they definitely replicate and adapt to their environment, viruses are more like androids than real living organisms. (
  • When a virus enters a cell but does not replicate immediately the situation is called? (
  • Following are some types of viruses that replicate by the lysogenic cycle, but also partly by the lytic cycle. (
  • Ø In last step, both cells containing single stranded DNA, replicate it and form double stranded F plasmid which is identical to the original one. (
  • The cholera cells will be returned to the environment, where they can replicate or to a new human host where it can also replicate. (
  • The tail fibers fix the base plate to the specific receptor site on the bacterial cell wall, and the tail sheath contracts like a syringe, forcing the DNA that is inside the virus through the cell wall and cell membrane. (
  • Plant and animal viruses can enter through endocytosis, in which the cell membrane surrounds and engulfs the entire virus. (
  • Some enveloped viruses enter the cell when the viral envelope fuses directly with the cell membrane. (
  • Some viruses also have an outer lipid bilayer membrane external to the coat called an envelope . (
  • For example, colds and influenza viruses destroy the mucous membrane in respiratory passages. (
  • Some viruses like Herpes virus derives their envelops from the nuclear membrane of host cell. (
  • By this method, the cells are shocked for the short time with an electric field of 10-20 kV/cm which will create holes in the cell membrane for the entry of plasmid DNA. (
  • Which type of virus would produce viral glycoproteins to be expressed on the host cell membrane? (
  • This envelope is made mostly of host cell membrane. (
  • Cell wall & factors affecting the cell wall synthesis, cytoplasmic membrane, etc. (
  • Aizenman E, Engelberg-Kulka H, Glaser G (1996) An Escherichia coli chromosomal "addiction module" regulated by guanosine 3′,5′-bispyrophosphate: a model for programmed bacterial cell death. (
  • Princeton molecular biologist Bonnie Bassler and graduate student Justin Silpe have identified a virus, VP882, that can listen in on bacterial conversations-and then, in a twist like something out of a spy novel, they found a way to use that to make it attack bacterial diseases like E. coli and cholera. (
  • B: One of the cells must be E. coli. (
  • Here the bacterial cell (E. coli) shows no immediate sign of infection and continues to grow and divide as nothing had happened. (
  • Until the 1930s the study of the obscure entities referred to as viruses was inseparable from the science of microbiology, a broader discipline that still encompasses the study of virology, bacteriology, mycology, botany, and zoology. (
  • Stabilization of CII promotes lysogeny, while its destabilization induces the lytic mode of development. (
  • A lysogenic bacterial culture can be treated with radiation or mutagens, inducing the cells to begin producing viruses and lyse. (
  • The viral replication cycle can produce dramatic biochemical and structural changes in the host cell, which may cause cell damage. (
  • Which of the following viruses is transcribed from RNA to DNA to RNA during the replication cycle? (
  • This information applies to common human coronaviruses and should not be confused with coronavirus disease 2019 (formerly referred to as … List of Viruses. (
  • While viral receptors experience negative selection to maintain their normal functions, they also undergo positive selection due to an everlasting evolutionary arms race between viruses and hosts. (
  • But it's become increasingly clear that many viruses cooperate, teaming up to co-infect hosts and break down antiviral immune defences. (
  • Different types of hosts that a virus will infect. (
  • Viruses can infect only certain species of hosts and only certain cells within that host. (
  • When the virus overhears that its hosts have achieved a quorum (right), the kill-stay decision protein is flipped to "kill" mode. (
  • There's an inherent risk in choosing the kill option: "If there are no other hosts nearby, then the virus and all its kin just died," she said. (
  • They may not all be listening in to this quorum-sensing information, but it is clear that these viruses can listen in to their hosts' information and then use that information to kill them. (
  • During the 1930s attenuated rinderpest vaccines were developed by passage of the virus in nonnatural hosts, e.g. rabbit and embryonated eggs (lapinized avian-ized) or goats (caprinized). (
  • Viruses infect organisms, or hosts, from all domains of life, and sometimes viral genomes become incorporated into the host DNA during an infection. (
  • It must instead use an existing pathway to invade the host cell, having evolved the tip of its tail to interact with a specific pore to allow entry of its DNA to the hosts. (
  • Despite the challenges encountered in inferring the identity of their hosts, we identified one virus predicted to infect members of the globally distributed SAR11 cluster. (
  • have demonstrated that the lysis of hosts by viruses releases cellular material (including carbon and nutrients) back into the microbial loop. (
  • One example of a productive cytocidal infection is the herpes virus. (
  • Chronic infections have similar cellular effects as acute cytocidal infections but there is a limited number of progeny and viruses involved in transformation. (
  • Some infected cells, such as those infected by the common cold virus known as rhinovirus, die through lysis (bursting) or apoptosis (programmed cell death or "cell suicide"), releasing all progeny virions at once. (
  • Virus reproduction requires that a virus particle infect an appropriate host cell and program the cellular machinery to synthesize the viral components required for the assembly of new virions, generally termed progeny virions or daughter viruses . (
  • Furthermore, viral replication through lysis is only beneficial to the virus if upon release, its progeny can infect other susceptible cells. (
  • Viral transformation is the change in growth, phenotype, or indefinite reproduction of cells caused by the introduction of inheritable material. (
  • Natural transformations can include viral cancers, such as human papillomavirus (HPV) and T-cell Leukemia virus type I. Hepatitis B and C are also the result of natural viral transformation of the host cells. (
  • Table 1: Cellular effects of viral infections Cytocidal infections are often associated with changes in cell morphology, physiology and are thus important for the complete viral replication and transformation. (
  • The simplest consideration is viral transformation of a bacterial cell. (
  • Some animal viruses enter host cell and permanently alter its genetic material resulting in cancer - transformation of the cell. (
  • virus-induced transformation). (
  • Agar suspension culture may be used for the analysis of cell transformation of palyoma virus. (
  • In molecular biology, transformation is the genetic modification of a cell by the direct uptake and expression of DNA from its surroundings usually through the liquid medium. (
  • Ø Divalent cation in cold conditions also weakens the cell surface structure so that transformation becomes easy. (
  • One process of DNA transfer, called transformation, involves the release of DNA into the environment by the lysis of some cells, followed by the direct uptake of that DNA by the recipient cells. (
  • There are currently only one genus ( Plasmavirus ), and one species in this family: the type species Acholeplasma virus L2 . (
  • The last time I talked to him, he was going back through a lot of the early science, to Peyton Rous and stuff, to try to get a background for the first concepts of viruses as causes of cancer, started the whole intellectual process going of what kinds of viruses, what species, what this, that, and the other. (
  • Somehow or other, Dick Shope always falls by the wayside, but Dick Shope did for DNA viruses in experimental species what Peyton Rous did for experimental species. (
  • Other species cannot enter the competent state but can be made permeable to DNA by treatment with agents that damage the cell envelope making an artificial trans-formation possible. (
  • Generalized transduction: Occurs during the lytic cycle of viruses. (
  • Genetic transduction is the virus-mediated transfer of nonviral genetic information to a recipient cell. (
  • In Transduction, DNA is transferred from one cell to another through the agency of viruses. (
  • How does specialized transduction differ from regular lysogeny? (
  • By another means of transfer, called transduction, the DNA is introduced into the recipient cell by a nonlethal virus that has grown on the donor cell. (
  • Plasmid - an extrachromosomal circular DNA molecule that autonomously replicates inside the bacterial cell. (
  • Cloning vector - a DNA molecule that carries foreign DNA into a host cell, replicates inside a bacterial (or yeast) cell and produces many copies of itself and the foreign DNA. (
  • Brum J ( 2017 ) Peer Review #2 of 'Determining virus-host interactions and glycerol metabolism profiles in geographically diverse solar salterns with metagenomics (v0.4)' . (
  • A virus is considered a noncellular organism consisting of DNA or RNA enclosed in a protein coat -- which normally includes some enzymes. (
  • Some viruses contain enzymes, and some have an outer membranous envelope. (
  • RNA viruses contain their own enzymes to initiate replication within the host. (
  • Here, the purported invention (by inventors Droge, Christ and Lorbach, collectively 'Droge') was dependent on the enzymes involved in lysogeny. (
  • Most RNA viruses carry which of the following enzymes? (
  • Viruses can be seen as obligate, intracellular parasites. (
  • Viruses have an obligate requirement for intracellular growth and a heavy dependence on host cell structural and metabolic components. (
  • Therefore, viruses are also referred to as obligate intracellular parasites. (
  • Viruses are obligate intracellular parasite. (
  • Some organisms, termed fastidious organisms, required specialised environments due to complex nutritional requirements, for example viruses are obligate intracellular parasites and require a growth medium containing living cells. (
  • Viruses, for example, are obligate intracellular parasites and require a growth medium containing living cells. (
  • Early studies revealed that the polylysogens underwent "conversion" to long filamentous cells that form tiny colonies on agar. (
  • Although the meaning of "virus" changed considerably from ancient Rome to the early decades of the twentieth century, traces of its original Latin usage can be found in expressions such as "the virus of racism," where it means something that poisons the mind, rather than a minute particle composed of nucleic acid and protein. (
  • Virologists have long studied their subjects in isolation, targeting cells with just a single viral particle. (
  • Outside of a living cell, a virus is a dormant particle. (
  • Viral particle that is capable of infecting a cell. (
  • Lysis and release of cellular material as dissolved organic matter is only the final step of a complex host-virus interaction where the invading pathogen can manipulate host metabolism and alter its phenotype to favour viral replication at the expense of host function. (
  • This implies that a protein complex or a polypeptide that is strange to the living thing inclination desire antigen processing and show nigh dendritic cells to lym- phocytes, a trade mark workings of adaptive or acquired insusceptibility Induction of astrocytic cyclooxygenase-2 in epileptic patients with hippocampal sclerosis A stint associated with PTSD is "survivor guilt. (
  • In such cases no virions are produced, and the infecting virus seems to disappear. (
  • Once inside the cell, the virions are uncoated. (
  • The virions attach to the surface of their host cell (a) . (
  • Many animal viruses, such as HIV (human immunodeficiency virus), leave the infected cells of the immune system by a process known as budding , where virions leave the cell individually. (
  • The infected host cell may produce hundreds to hundreds of thousands of new virions, usually accompanied by cell death. (
  • These virions develop envelops and budded off from the host cells. (
  • 1. virions attach to the host cells. (
  • Future studies will be focused on whether this same strategy is used by viruses that infect eukaryotic cells, such as human. (
  • Methods for culturing HCV in eukaryotic cells. (
  • Comparison of prokaryotic and eukaryotic cells. (
  • The technology involved recombination of exogenous DNA introduced into eukaryotic cells. (
  • Cells with transforming infections undergo immortalization and inherit the genetic material to produce tumors. (
  • The lysogenic cycle happens when a virus infiltrates a cell but rather than quickly hijacking it, the virus inserts its genetic material instead to the host DNA. (
  • All viruses have is a protein coat and a core of genetic material, either RNA or DNA. (
  • Most viruses have either RNA or DNA as their genetic material. (
  • However, such alterations occur because organisms exchange genetic material, thereby permitting combinations of mutations to be collected in individual cells. (
  • In addition to restriction of lytic replication, SpnIII also led to abortive infection in the majority of host cells. (
  • Today a virus is defined as a minute entity composed of an inner core of nucleic acid contained in a protein envelope. (
  • In which step does the virus acquire this envelope? (
  • This virus has a single, positive sense strand of RNA, and possesses an envelope. (
  • Without aimR, the expression of aimX is greatly reduced, relieving the repression for lysogeny. (
  • Ø In this process recipient cells are able to take up double stranded DNA by the physical and chemical processes. (
  • This work also elucidates the effects of oncogenic viruses on cell surface metabolism. (
  • The cellular metabolism becomes so altered that it helps to produce thousands of new viruses. (
  • however, we have only just begun to document the diversity, host range and infection dynamics of marine viruses, as well as the subsequent effects of infection on both host cell metabolism and oceanic biogeochemistry. (
  • Here, the infecting virus increases host fitness through phenotypic augmentation in order to ride out the metaphorical storm, with a concomitant impact on host substrate uptake and metabolism, and ultimately, their interactions with their wider microbial community. (
  • Once a virus has overcome host defences, lytic viral infection typically involves a shut-down of host metabolism, followed by degradation of macromolecules and scavenging of intracellular resources. (
  • Viruses have been shown to impact microbial populations through a myriad of processes, including cell lysis and reprogramming of host metabolism. (
  • Our results show that rumen viruses have implications for understanding the structuring of the previously identified core rumen microbiota and impacting microbial metabolism through a vast array of AMGs. (
  • Collectively, the results of this jointly theoretical and experimental study along with other observations support the hypothesis that persistence is the product of many different kinds of errors in cell replication that result in transient periods of non-replication and/or slowed metabolism by individual cells in growing populations. (
  • However, these results might reflect inherited flow cytometry and nucleic acids multiple displacement amplification biases toward large dsDNA viruses (e.g. myoviruses). (
  • Nucleic acids of viruses. (
  • They can also be used to steal information, harm computers … These variations in the nucleic acids of viruses form one central criterion for classification of all viruses. (
  • New viruses develop new nucleic acids, capsids and spike. (
  • Their nucleic acids are injected into the cell. (
  • Viruses are key components of microbial assemblages, hence, the need to investigate them to better understand the deep biosphere's ecology. (
  • In this study, we performed genomic analysis of 27 targeted flow cytometry-sorted viruses and 3 microbial cells from a one-milliliter hydrothermal fluid sample collected from IODP Hole U1362B CORK observatory at the Juan de Fuca Ridge (JFR) eastern flank. (
  • Like the pirates of the 17th and 18th centuries that hounded ships plying major trade and exploration routes, viruses have evolved mechanisms to hijack microbial cells and repurpose their cargo and indeed the vessels themselves to maximise viral propagation. (
  • However, little is known about the processes shaping the distribution of rumen viruses or how viruses may modulate microbial-driven processes in the rumen. (
  • While there is a growing understanding of the importance of rumen microbes in regard to ruminant health and productivity, the roles of viruses in shaping rumen microbial communities and in turn ecosystem function are not well established. (
  • Viruses, Evolution and Cancer: Basic Considerations focuses on comparative biology and evolutionary aspects of DNA and RNA oncogenic viruses. (
  • In my biol 105 class we discussed the evolutionary benefits of lysogeny. (
  • Suttle, C. Marine viruses - major players in the global ecosystem. (
  • Brum, J. R., Schenck, R. O. & Sullivan, M. B. Global morphological analysis of marine viruses shows minimal regional variation and dominance of non-tailed viruses. (
  • An empirical model of carbon flow through marine viruses and microzooplankton grazers. (
  • Assuming an average size of 100 nm in length, placed end-to-end marine viruses would stretch to our nearest neighbour star (Proxima Centauri, 4.22 light years away) and back. (
  • Thus, marine viruses are a major component of global carbon cycling. (
  • 1995. Marine viruses. (
  • The role of marine viruses in the carbon cycle and in maintaining diversity in bacterial, archaeal, and eukaryotic populations in the ocean is critical ( 1 - 3 ). (
  • Immunity, like virus, is a Latin term with many meanings that has been adapted to biomedical science. (