A A-type inclusion body. Inclusion bodies pro­ abortive transformation. A TRANSFORMATION of duced late in infection in the cytoplasm of cells in­ cells which is unstable so the cells revert to fected with certain pox viruses (e.g. fowlpox, normal after a few generations. ectromelia, cowpox, canarypox). Some contain virus particles. In cowpox virus infections the abras virus. Family Bunyaviridae, genus inclusions consist almost entirely of a single pro­ Bunyavirus. tein species (mw. 160 x 103), abundantly synthe­ sised late in infection. Cytoplasmic A-type inclu­ Abraxas grossulariata Cytoplasmic Polyhe­ sions of some vertebrate poxviruses (e.g. drosis Virus. CYTOPLASMIC POL YHEADROSIS VIRUS fowlpox) resemble POLYHEDRA in several proper­ ( CPV) isolated in the United Kingdom from larvae ties as they contain virus particles, are infective, of the magpie moth, Abraxas grossutariata can be isolated intact, are resistant to digestion by (Geometridae, Lepidoptera). The virus is the type some proteases and are extremely resistant to member of 'type 8' CPVs. Unrelated to Bombyx prolonged storage. mori (type I) CPV on the basis of RNA electro­ Patel, D.O. et at. ( 1986) Virology 149, 174. pherotype. Viruses of similar electropherotype have been observed in other Lepidoptera (see A-type virus particle. A term used originally for APPENDIX B). a morphologically defined group of RNA virus Payne, C.C. and Mertens, P.P.C. (1983) In The particles, often found in tumour cells. They are Reoviridae. p. 425. ed. W.K. Joklik. Plenum double-shelled spherical particles with a diameter Press: New York. of 65-75 nm. for the outer and 50 nm. for the inner shell; the inner ring appears denser. Various Absettarov virus. Family Ftaviviridae, genus members of RETROVIRIDAE have A -type particles. F/avivirus. Isolated from a boy with biphasic See B-, C-, D-TYPE VIRUS PARTICLE. fever and signs of meningitis. Tick-borne. Found Dalton, A.J. (1972) J. Natl. Cane. Inst. 49, 323. in many countries. Pathogenic in Rhesus mon­ keys. AAB. See CMI/AAB. absorbance. Amount of light absorbed by a Abadina virus. Family Reoviridae, genus Orbi­ substance at a particular wavelength. It virus. Isolated from Culicoides. has no official units although the term optical density units is often used. See SPECIFIC ABSOR­ Abelson leukaemia virus. Family Retroviridae, BANCE. subfamily Oncovirinae, genus Type C Oncovirus, sub-genus Mouse type C Oncovirus. A virus iso­ absorption spectrum. Graphical representation lated from Balb/c mice inoculated with Moloney of ABSORBANCE of a substance at different wave­ leukaemia virus. Produces lymphoid leukaemia lengths. Valuable in obtaining an approximate and can transform mouse cells in vitro. Requires estimate of the percentage of nucleic acid in a a helper virus for virus replication. Risser, R. et at. virus from the ratio of absorbances at 254 and 280 (1978)J.exp.Med. 148,714. nm. Spectral characteristics of nucleotides can be found in Sober, H.A. ed. (1968) Handbook of abortive infection. An infection which does not Biochemistry: Selected Data for Molecular Biol­ produce infectious progeny. The cell may not ogy. CRC Press: Cleveland, Ohio. allow the expression of all the viral genes or the virus may be defective. Abu Hammad virus. Family Bunyaviridae, R. Hull et al., Virology © Palgrave Macmillan, a division of Macmillan Publishers Limited 1989 2 Abu Mina virus. genus Nairovirus. Isolated from a tick Argas bound to ds nucleic acid and orange if bound to ss hermanni in Egypt. nucleic acid. Abu Mina virus. Family Bunyaviridae, genus acriflavine. A dye which inactivates viruses in Nairovirus. the presence oflight (photodynamic inactivation) by binding to nucleic acid. Also used as an ANTI­ abutilon mosaic virus. A possible Gemini­ BIOTIC. virus, subgroup B. Jaske, H. and Schuchalter-Eicke, G. (1984) acronym. A word created from the initial letters Phytopath. Z. 109, 353. of the principal words in a compound term, e.g. enteric cytopathic human orphan virus = ECHO acado virus. Family Reoviridae, genus Orbi­ virus. virus. Isolated from Culex antennatus and Culex univittatus neavi in Ethiopia. acrylamide. A chemical which is polymerised using a cross-linking agent to give polyacryl­ acara virus. Family Bunyaviridae, genus amide, one of the most commonly used supports Bunyavirus. Isolated from sentinel mice Culex for GEL ELECTROPHORESIS. sp. and Nectomys squamipes in Brazil and Pan­ ama. Actias selene Cytoplasmic Polyhedrosis Virus. Cytoplasmic polyhedrosis virus (CPV) isolated acholeplasmavirus. Virus isolated fromAchole­ in the UK from laboratory-reared larvae of Actias plasma sp. e.g. phages Ll, L2 and L3. selene bred from pupae obtained from a site in the Himalayas. The virus is the type member of 'type AcMNPV. Abbreviation for Autographa cali­ 4' CPVs. UnrelatedtoBombyxmori(type l)CPV fornica nuclear polyhedrosis virus. on the basis of RNA electropherotype. Viruses of similar electropherotype have been observed in other Lepidoptera (see APPENDIX B). AcNPV. Abbreviation for Autographa califor­ Payne, C.C. and Mertens, P.P.C. (1983) In The nica nuclear polyhedrosis virus. Reoviridae. p. 425. ed. W.K. Joklik. Plenum Press: New York. acquired immunodeficiency syndrome (AIDS). A disease of man caused by HUMAN actinomycin D. A compound which inhibits IMMUNODEFICIENCY VIRUS (HIV). AIDS is primarily transcription by interacting with the guanine a disease of the immune system so the infection residues of helical DNA. Replit-ation of DNA­ usually results in a wide range of adverse containing viruses and those RNA viruses which immunological and clinical conditions. The require DNA to RNA transcription (e.g. RETRO­ opportunistic infections (i.e. those caused by VIRIDAE, INFLUENZA VIRUS) is inhibited, while micro-organisms that seldom cause disease in replication of other RNA-containing viruses is persons with normal defence mechanisms) and unaffected. cancers resulting from immune deficiency are generally the most severe but neurological problems such as dementia resulting from actinophages. Viruses infecting members of the infection of the brain can also occur. It is now re­ order Actinomycetales (filamentous, branching cognised that the disease is likely to be fatal. The bacteria; e.g. Streptomyces, Nocardia, Myco­ disease is generally transmitted sexually but is bacterium) and related organisms including also prevalent among drug addicts and occurs Corynebacterium, Arthrobacter and Kurthia. All occasionally in children from infected mothers of the virus isolates of known morphology from and in patients receiving blood transfusions. It these hosts are TAILED PHAGES (see PHAGE). can be controlled by AZT (AZIDOTHYMIDINE) but the side effects of the drug are not negligible. activator. In molecular biology an activator is a protein which binds to DNA upstream of a gene acridine orange. A compound used for deter­ and activates transcription of that gene. mining the nature of the nucleic acid in virus particles or cells. It binds to the nucleic acid and, active immunity. Immunity induced by injec­ when exposed to UV -light, fluoresces green if tion of a virus or virus subunit. adenosine 5'-monophosphate 3 H H 0 CH3i-CH. CH.-y-cH. 0 ~-H H-~ N-CH3 N-CH3 ~~ I I Sarcosine Sarcosine I I 0 •. Proline ~.-Proline I I l ""Valine ""V&line y=oI f=oI CH3-HC-----r-H H-~-----CH-CH. NH NH !=o ·~~ o¥o • CH3 Actinomycin acute bee-paralysis virus. See BEE ACUTE adenine. A constituent purine base of DNA and PARALYSIS VIRUS. RNA. See NUCLEIC ACID. acute epidemic gastroenteritis virus of man. adenine arabinoside. See ARABINOSYL ADENINE. Unclassified. Consists of a group of viruses, Norwalk, Hawaii and Wollan. Viruses are c.30 adeno-associated virus. (Latin 'dependere' =to nm. in diameter and are acid- and ether-stable. depend.) A genus in the family Parvoviridae. They are found in faeces by electron microscopy. Replication is dependent on a helper adenovirus Flewett, T.H. (1977) Rec. Adv. clin. Virol. 1, for complete virus replication. Multiplies in cells 151. which support adenovirus replication. The virus particles contain either + or - DNA which are complementary and anneal to form dsRNA on acute haemorrhagic conjunctivitis virus. Fam­ extraction. Occurs in many species. Now known ily Picornaviridae, genus Enterovirus. Desig­ as the Dependovirus genus. nated enterovirus 70. Causes acute haemorrhagic conjunctivitis in man in many parts of the world. adenosine. A nucleoside of adenine and ribose. Grows in several cell lines. See NUCLEIC ACID. acute laryngo-tracheo-bronchitis virus. See adenosine S' -monophosphate. Monophosphate PARAINFLUENZA VIRUS type 2. of the nucleoside ADENOSINE. Acyclovir acyclovir. (Synonym: acycloguanosine; Zovi­ rax). An antiviral agent with a potent and specific action against HERPES VIRUS I and 2, both in vitro N~N and in vivo. The compound is selectively .4.. JLN~ PHOSPHORYLATED by herpes virus-induced H,N N I THYMIDINE KINASE. The phosphorylated derivative inhibits herpes virus-induced DNA polymerase. Hove~ 4 adenosine 5'-triphosphate adenosine 5'-triphosphate. Triphosphate of the AdoHcy. Abbreviation for S-adenosyl homocys­ nucleoside ADENOSINE. See NUCLEIC ACID. teine. adenosine triphosphatase (ATPase). An en­ AdoMet. Abbreviation for S-adenosyl methion­ zyme which catalyses the conversion of ATP to ine. Synonym: SAM. ADP with the release of Pi. Some viruses (e.g. vACCINIA) possess an ATPase activity. adonis mosaic virus. An unclassified plant vi­ rus, isometric particles, occurs in Japan. Adenoviridae. (Greek 'aden', 'adenos' =gland.) Doi, Y. Personal communication. A family of DNA viruses with isometric particles 70-90 run. in diameter which sediment at c.SOOS adsorption. The fmt stage of infection of a cell and band in CsCI at 1.33-1.35 glee. The capsid is by a virus involves attachment at a receptor site. Often involves a specific interaction between a receptor on the cell surface and a component of the virus. It is independent of temperature. adventitious virus. A foreign virus present in a vaccine or preparation of a different virus. adzuki bean mosaic virus. See COWPEA APHID­ BORNE MOSAIC VIRUS. formed of 252 capsomeres, 8-9 nm.