Submitted to: International Symposium on Emerging and Re-Emerging Pig Diseases
Publication Type: Proceedings
Publication Acceptance Date: April 24, 2003
Publication Date: June 29, 2003
Technical Abstract: During porcine circovirus (PCV) replication in PK15 cells, nine PCV type 2 (PCV2)-specific RNAs are synthesized. They include the capsid RNA (CR), five Rep-associated RNAs (Rep, Rep', Rep3a, Rep3b, Rep3c), and three NS-associated RNAs (NS515, NS672 and NS0). In this work, the results demonstrated that a stop codon introduced at the very 5'-end of CR did not affect Rep-associated antigens or viral DNA synthesis. Altering the consensus dinucleotides at the splice junctions of the minor RNAs (Rep3a, Rep3b, Rep3c, NS515 and NS672) or introducing a stop codon in the abundant NS0 RNA also did not have any affect on viral protein synthesis or DNA replication. However, mutations that resulted in truncated Rep or Rep' proteins caused greater than 99% reduction of protein synthesis and complete shut down of viral DNA replication. These results demonstrated that both Rep and Rep' are absolutely essential for PCV2 replication.