MORPHOLOGY AND MORPHOGENESIS OF HEPATITIS-E VIRUS (STRAIN 87A)

The morphology and morphogenesis of isolated hepatitis E virus (HEV, s train 87A) were observed by electron microscopy (EM) and immune electr on microscopy (IEM). Progressively developing local vesicles, virions accumulation in crystalline arrays and viroplasmic focus were seen in cytoplasm of infected cells. Replication and assembly of the new gener ation viruses were closely associated with rough endoplasmic reticulum (RER), inclusion body (IB) and microfibrils. Condensation and margina tion of chromatin, dispersion of nucleolar material, nuclear membrane alteration and masses of threads, granular material, and fibrillar com ponent of the nucleus were frequently found. These changes revealed th at this strain virus was confirmed as a RNA virus. The shape of the vi rus particles appeared approximately spherical whether the specimens w ere from the tissue culture crude suspension or purified highly concen trated preparations. The size of the virion was about 30 nm in diamete r. The viral particles appeared unsmooth and irregular in outline. The spike-like structures may be occationally observed on the surface of some viral capsides. The diameter of the strain 87 A virus is larger t han the picornavirus and smaller than the calicivirus. This strain vir us is different from classical calicivirus in without the cup-shaped s urface depressions. The new genus, heparnavirus genus of caliciviridae family should be proposed for HEV.