RESUMO
Some genetic and biological properties of the multiploid -forming mutant of Venezuelan equine encephalomyelitis virus as well as of standard and multiploid virions isolated from its population were analysed. The mutant steadily retained the capacity for formation of multiploid virions comprising up to 20% of the population both in passages in CEF culture and in the progeny of multiploid and standard virions. Owing to this, the concentration of multiploid virions in the population of this mutant remains at a constant level. Formation of multiploid virions compensates for the temperature-sensitive defect inherent in the standard virions which is associated with later stages of virus replication.
Assuntos
Vírus da Encefalite Equina Venezuelana/fisiologia , Mutação , Poliploidia , Animais , Embrião de Galinha , Vírus da Encefalite Equina Venezuelana/genética , Vírus da Encefalite Equina Venezuelana/isolamento & purificação , Fenótipo , Temperatura , Ensaio de Placa Viral , Vírion/genética , Vírion/isolamento & purificação , Vírion/fisiologia , Cultura de VírusRESUMO
Multiploid virions present in the population of multiploid-forming mutant of Venezuelan equine encephalomyelitis (VEE) virus were isolated from preparations of purified and concentrated virus by methods of zonal centrifugation in glycerin density gradient or gel filtration through biogel A-150 m. The portion of multiploid particles in such preparations reached 70%-90%. The isolated multiploid virions retained their morphology, infectivity and hemagglutinating activity. The multiploid particles were found to differ from standard virions in the sedimentation rate and buoyant density.
Assuntos
Vírus da Encefalite Equina Venezuelana/isolamento & purificação , Vírion/genética , Vírion/isolamento & purificação , Animais , Embrião de Galinha , Cromatografia em Gel , Vírus da Encefalite Equina Venezuelana/genética , Microscopia Eletrônica , Mutação , Cultura de VírusRESUMO
An electronmicroscopic study of a suspension of Venezuelan equine encephalomyelitis (VEE) virus by freeze-drying and freeze-etching methods showed that glycoprotein peplomers are located on the surface of the lipoprotein shell. These peplomers are organized with trimer clustering in a T = 4 icosahedral surface lattice. The mode of glycoprotein clustering for the two clones of VEE are different.