Systematic Veterinary Virology

REPLICATION

• Poxvirus replication occurs in the cytoplasm. The virus has all the enzymes necessary for genome replication and hence do not depend on the host cell nucleus. Replication is simple and straightforward. Entry is by endocytosis and there are more than one receptor in the cell for attachment.
• Penetration is complex and involves more than one mechanism. Uncoating occurs in two stages. Removal of the outer membrane occurs as the particle enters the cell and the inner membrane is removed as the core passes into the cytoplasm.
• After uncoating the enzymes required for viral genome are produced (early transcription and translation). This is followed by genome replication. Late transcription and translation occurs following this and proteins produced are mostly structural proteins. Assembly occurs in the cytoskeleton and the events involved in putting together such a complex particle are not understood.