Replication of porcine circoviruses

• Main Authors: Grasland Béatrice, Dory Daniel, Faurez Florence, Jestin André
• Format: Article
• Language: English
• Published: BMC 2009-05-01
• Series: Virology Journal
• Online Access: http://www.virologyj.com/content/6/1/60

<p>Abstract</p> <p>Porcine circoviruses are circular single-stranded DNA viruses that infect swine and wild boars. Two species of porcine circoviruses exist. Porcine circovirus type 1 is non pathogenic contrary to porcine circovirus type 2 which is associated with the disease known as Post-weaning Multisystemic Wasting Syndrome. Porcine circovirus DNA has been shown to replicate by a rolling circle mechanism. Other studies have revealed similar mechanisms of rolling-circle replication in plasmids and single-stranded viruses such as <it>Geminivirus</it>. Three elements are important in rolling-circle replication: i) a gene encoding initiator protein, ii) a double strand origin, and iii) a single strand origin. However, differences exist between viruses and plasmids and between viruses. Porcine circovirus replication probably involves a "melting pot" rather than "cruciform" rolling-circle mechanism.</p> <p>This review provides a summary of current knowledge of replication in porcine circoviruses as models of the <it>Circovirus </it>genus. Based on various studies, the factors affecting replication are defined and the mechanisms involved in the different phases of replication are described or proposed.</p>