Rainbow trout virus RTV A strain of

Epizootic hematopoietic necrosis virus in the genus Ranavirus.

Raji cells (CCL 86) A lymphoblastoid cell line established from a Burkitt's tumor of the maxilla in an 11-year-old black boy. Grows in suspension. The majority of the cells in culture contain the EBNA antigen.

Ranavirus A genus in the family Iridoviridae, type species Frog virus 3. Particle diameter is 130 nm in thin section. The capsid has skew symmetry with T = 133 or 147. Viruses grow in avian, fish or mammalian cells and rapidly shut off host cell macromolecular synthesis. The DNA genome is 170kb in length, G+C is 53%; highly methylated (25% of dC residues). It is terminally redundant and circularly permuted. At present Frog virus 3 is the only recognized species in the genus, but there are many tentative species members which share sequences with the gene for the major capsid protein of FV-3, and await further investigation. Primers for PCR amplification of Ranavirus sequences have been described.

Goorha RM and Granoff A (1999) In Encyclopedia of Virology, Second edition, edited by A Granoff and RG Webster. London: Academic Press, p. 582 Mao J et al (1997) Virology 229, 212

Rangifer tarandus herpesvirus Synonym for Cervid herpesvirus 2.

ranid herpesvirus 1 (RaHV-1) An unas-signed virus in the family Herpesviridae. A natural infection of Rana pipiens in north, central and north-eastern parts of the USA and adjacent southern Canada. Causes renal carcinoma in these frogs, which may affect up to 90% of the population. The disease is seasonal, and frogs excrete virus in urine when they are kept at 4°C but not if kept at 25°C. The virus also induces tumors experimentally in the kidneys of Rana pipiens, R. clamitans and R. palustris. The DNA genome is small for a herpesvirus (mol. wt. 66 x 106

by contour length measurement), with a G+C content of 45%. The virus has not been grown in cell cultures. Synonym: Lucke frog herpesvirus.

Granoff A (1983) In The Herpesviruses, vol. 2, edited by B Roizman. New York: Plenum Press, p. 367

ranid herpesvirus 2 (RaHV-2) An unas-signed virus in the family Herpesviridae. Isolated from the urine of Lucke tumor-bearing frogs, but genetically and antigenically distinct from ranid her-pesvirus 1. Not oncogenic. DNA mol. wt. 77 x 106. G+C content 56%. Grows in frog embryo cell cultures at 25°C. Synonyms: frog herpesvirus 4; frog virus 4.

Granoff A (1999) In Encyclopedia of Virology, Second edition, edited by A Granoff and RG Webster. London: Academic Press, p. 51

ranikhet disease virus Synonym for

Newcastle disease virus.

RANTES Regulation upon Activation Normal T cell Expressed and Secreted. A beta chemokine.

Rat coronavirus (RtCoV) A species in the genus Coronavirus. Isolated from rats with sialodacryoadenitis. A natural infectious disease of rats, easily missed as it has a low mortality. There is fullness of the neck due to enlargement of the salivary glands. The submaxillary, salivary and Harderian glands are the glands mainly involved and there is necrosis of the ductal epithelium with acute lymphocytic infiltration and gelatinous edema. Seromucinous glands are not affected. Red tears and staining of the fur around the eyes due to porphyrins, excreted in tears, may occur. There is repair of the tissues which is complete in 2 weeks. Injection i.c. into newborn mice causes ataxia, paralysis and death 10 days after injection. Four-week-old mice are resistant. Antigenically related to mouse hepatitis virus. Does not agglutinate erythrocytes of mice, chickens, humans, sheep, rabbit, guinea pig or goose. Can be propagated in suckling rats and mice or adapted to replicate in primary rat kidney cell cultures with the formation of multinucleate giant cells. Synonym: sialodacryoadenitis virus of rats.

Bhatt PN et al (1972) J Infect Dis 126, 123

rat cytomegalovirus (RCMV) Synonym for Murid herpesvirus 2.

rat encephalomyelitis virus (REV) A strain of Theilovirus in the genus Cardiovirus.

rat parvovirus See Kilham rat virus.

Rat polyomavirus A possible species in the genus Polyomavirus. Isolated from an athymic nude rat, in which it caused sialoadenitis.

rat rotavirus See Rotaviruses group A and B.

rat sarcoma virus A possible species in the genus Gammaretrovirus. A stable transforming virus of rat origin formed by the combination of a rat ecotropic type C virus with src genes.

Rasheed S et al (1978) Proc Natl Acad Sci 75, 2972

rat submaxillary gland virus Synonym for Murid herpesvirus 2.

rat type C retrovirus A possible species in the genus Gammaretrovirus. An endogenous non-oncogenic virus designated WF-1 was spontaneously released by a cell line WF derived from a normal Wistar-Furth rat embryo. Closely related to two viruses (R-35 and RNTDV) produced by cell lines derived from rat mammary tumor tissue. All three are morphologically and antigenically similar but only rat mammary tumor-derived virus (RMTDV) causes leukemia on injection into rats. Can provide coat proteins which renders mouse sarcoma virus oncogenic for the rat.

Bronson DL et al (1976) Proc Soc Exp Biol Med 152, 116

rat virus R Synonym for Kilham rat virus, in the genus Parvovirus.

rattlesnake orthoreovirus (RRV) A tentative species in the genus Orthoreovirus. Isolated from the brain of a rattlesnake with central nervous symptoms. Causes syncytial giant cells in Vero cell culture. The genome contains 10 segments of double-stranded RNA.

Vieler E et al (1994) Arch Virol 138, 341

RD114 virus rate zonal centrifugation A form of density gradient centrifugation. As the particles begin to sediment under the influence of centrifugal force, they become separated into different zones, each containing particles of similar sedimentation rate. Particles studied by this technique should have a density greater than that at any point in the supporting gradient column, and the run should be brought to an end before any separate zone reaches the bottom. See also isopycnic gradient cen-trifugation.

Rauscher leukemia virus A strain of Murine leukemia virus in the genus Gammaretrovirus, related to Friend murine leukemia virus. Obtained by passage of filtrates of leukemia mouse tissue in newborn BALB/c mice. A defective virus requiring a helper leukemia virus for replication. Genome contains specific leukemia-producing sequences very like or identical to those in Friend virus spleen focus-forming virus and other sequences related to a different helper virus.

RAV Rous-associated virus.

RAV-0 virus An endogenous chicken virus which replicates in some chicken cells, but very poorly, and does not cause any disease in chickens; this is probably related to its LTR sequences. Belongs to subgroup E of chicken leukosis sarcoma viruses. Recombination with horizontally transmitted wild strains of virus leads to a very virulent virus. Indistinguishable from RAV-60 in its envelope properties.

Robinson HL et al (1980) Cold Spring Harbor Symp Quant Biol 44, 1133

RAV-60 virus A Rous-associated virus in the genus Alpharetrovirus, isolated when fowl cells with the chick helper factor were infected with an avian leukemia virus RAV-1 or RAV-2. It belongs to subgroup E of the chicken leukosis sarcoma virus. Propagates very much more rapidly in quail cells than RAV-0 does but is indistinguishable from RAV-0 in its envelope properties. Unlike RAV-0, it causes leukosis in chickens.

Hanafusa T et al (1970) Proc Natl Acad Sci 67, 1797

Raza virus (RAZAV) A serotype of Hughes virus in the genus Nairovirus. Not reported to cause disease in humans.

Razdan virus (RAZV) A tentative virus in the family Bunyaviridae. Isolated in suckling mice from a pool of female ticks, Dermacentor marginatus, collected from sheep in Razdansk Region, Armenian SSR. Diameter 100 nm by electron microscopy. Infectivity not sensitive to 5-bromo-2-deoxyuridine but sensitive to ether. Hemagglutinates goose erythrocytes. Not reported to cause disease in humans.

Rb tumor suppressor proteins Retino-blastoma susceptibility gene products, a family of 100-130kDa proteins involved in cell growth regulation and tumor suppression. Oncogenic viruses such as adenovirus, SV40 and papillomaviruses produce proteins which bind to Rb proteins and inactivate them, resulting in cell transformation and neoplasia. See pRb

R2C cells (CCL 97) A steroid-secreting cell line derived from a transplantable Leydig cell tumor of a rat.

RD cells (CCL 136) A cell line established from a malignant embryonal rhabdo-myosarcoma of the pelvis of a 7-year-old Caucasian female.

RD114 virus A strain in the genus Gammaretrovirus isolated when a human rhabdomyosarcoma cell line (RD) was passed in cat fetuses developing in utero. One kitten at birth contained RD tumor cells which were producing a type C oncovirus. Differs in major species-specific protein and reverse transcriptase from exogenous cat type C virus, but very similar or identical to feline endogenous type C retrovirus. It is a xenotropic virus unable to infect cat cells and was at first thought to be a human virus. No association with disease. Multiple copies of RD114 viral genomes are found in all domestic cat cells, but these are not normally expressed. Most wild cats do not have these endogenous sequences. The virus is related to an endogenous retrovirus of baboons, and may have been acquired from African primates several million years ago. Receptors for RD114 virus have been

RD114 virus

identified on human cells, and the virus is being used experimentally as a pseudotype vector for therapeutic gene transfer into human hematopoietic stem cells.

Kelly PF et al (2000) Blood 96, 1206 Niman HL et al (1977) Nature 226, 357

RDE Receptor-destroying enzyme. See neu-raminidase.

reactivation A special type of recombination. When one or more of the virus particles involved in a multiple infection is inactivated, and unable alone to initiate a productive cycle, it nevertheless can contribute to the production of progeny virus with the assistance of the other viruses, i.e. it is 'reactivated'. When the virus particles involved differ genetically, the process is known as 'cross-reactivation' or 'marker rescue'. If they are genetically identical and all are inactivated, the process is known as 'multiplicity reactivation'. 'Non-genetic reactivation' is in fact not a case of reactivation, but a special example of complementation of a virus inactivated by damage to its proteins rather than its genome nucleic acid. See Berry-Dedrick phenomenon.

reading frame A sequence of codons in RNA or DNA beginning with the initiation codon AUG. See open reading frame.

readthrough The reading of an mRNA through a stop codon. A suppressor tRNA causes the insertion of an amino acid into a growing polypeptide chain in response to the stop codon. The readthrough protein is thus longer than the usual polypeptide. See also protein synthesis, ribosomal frameshifting.

reannealing The coming together of complementary strands of nucleic acid after separation by melting. See hybridization.

reassortants Viruses which have derived parts of their genomes from two viruses involved in a mixed infection. This process is particularly likely to occur with viruses which have multisegmented genomes, such as Orthomyxoviridae and Reoviridae.

receptor A site or structure on the cell surface to which a virus binds. A host surface component that participates in virus binding and facilitates viral infection. See CD.

Haywood AM (1994) J Virol 68, 1

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