Systematic Veterinary Virology

MORPHOLOGY

• Rinderpest virus is pleomorphic. It is single stranded, negative sense RNA viruses. They are enveloped viruses and are ether sensitive. They possess helical symmetry. 
• Virus measures approximately 100 to 300 nm in diameter. The envelopes are covered with minute projections, which are the surface glycoproteins (H and F proteins) responsible for cell attachment and fusion.
• Rinderpest virus is differentiated from PPR virus (PPR is a very important infection resembling rinderpest in small ruminants) through nucleic acid probes for N gene.
• In total The virus has 6 important proteins and two non-structural proteins. They are
• N - nucleocapsid protein which covers and protects the virion RNA
• P- polymerase-associated or phosphoprotein
• M- matrix protein, interacts with cytoplasmically located nucleocapsids and membrane associated glycoproteins in cell envelope to produce virus bud
• F - fusion protein enables virus and host cell membrane to fuse
• H - haemagglutinin or attachment protein, enables virus to attach to host cell membrane
• L - large protein, acts as a virus transcriptase and replicase in association with P protein
• C/V - two non-structural virus-encoded proteins produced in infected cells, may have function in virus reproduction
• The H and F proteins are very important in establishing the infection. H is responsible for attachment and F is responsible for entry into the cell.