[Genetic variation analysis of SARS coronavirus]

Abstract

Severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) has been verified as the causative agent of a worldwide outbreak of SARS. Since the observed per-base replication error-rate of RNA polymerase is about 3 x 10(-5), RNA virus populations typically contain genetic variants that form a heterogeneous virus pool. This feature confers great adaptability on viruses and is partly responsible for current difficulties of viral disease prevention and control, such as of HIV and HCV infections. SARS-CoV, a newly-identified single-strand RNA virus, has been identified with common variable property of RNA viruses. In this study, genetic variation of SARS-CoV is analyzed based on available documented data and our study. It suggests that SARS-CoV is of similar mutation frequency and dynamic mutant distributions like other RNA viruses, though relatively less identified variation number than those causing chronic infections. In contrast, the viral spike (S) gene exhibits high variation, while nucleocapsid (N) gene shows relative sequence conservation. No obvious correlation is observed between viral variation and clinical disease manifestation from present analyzed data.