Systematic Veterinary Virology

MORPHOLOGY

• Morphological features are typical of other members of the family coronaviridae. The virions are enveloped and slightly pleomorphic or spherical in shape. The surface of the virus has surface projections, which are distinct and club-shaped. The nucleocapsid is filamentous with helical symmetry. The virions contain one molecule of linear positive-sense single stranded RNA, which also act as mRNA. The virus has five structural proteins – S, M, N, HE and E