Feline syncytium-forming virus: identification of a virion associated reverse transcriptase and electron microscopical observations of infected cells.
The maturation of feline syncytium-forming virus (FSFV), a member of the foamy virus sub-family (Spumavirinae), has been studied by electron microscopy of thin sections of infected feline embryo (FEA) cells. The initial event observed was formation of crescent-shaped nucleoids at the plasma membrane. As budding progressed, the nucleoid became circular in outline with an electron-lucent centre in fully mature extracellular particles. These observations suggested that the maturation of FSFV in fully permissive FEA cells resembled that of C-type RNA tumour viruses, rather thant the B-type mouse mammary tumour virus. In this respect FSFV may be distinct from other foamy viruses. However, like other foamy viruses FSFV possessed reverse transcriptase activity. Polymerase activity co-sedimented with infectivity in an equilibrium density gradient and exhibited a preference for poly(rA).oligo(dT)10 over poly(dA).oligo(dT)10 as exogenous template.
D000818:Animals; D002415:Cats; D002460:Cell Line; D002462:Cell Membrane / Q000382:microbiology; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism*; D012190:Retroviridae / Q000254:growth & development*; D016092:Spumavirus / Q000201:enzymology / Q000254:growth & development* / Q000648:ultrastructure; D014779:Virus Replication
D012194:RNA-Directed DNA Polymerase