MUTATION: The gene 3 is intact in the two virulent PRCV isolates, whereas gene 3 is altered in the two low virulence isolates. A similar observation has been reported for TGEV as a nonpathogenic TGEV mutant with a small plaque morphology had a deletion in gene 3. We have also observed that one of the low virulence PRCV isolates, IA 1894, which has a deletion in gene 3, replicates poorly in cell cultures. Collectively these studies suggest that gene 3 may be an important determinant for in vivo virulence and in vitro replication of coronaviruses (Paul et al., 1997).
References
Paul et al., 1997: Paul PS, Vaughn EM, Halbur PG. Pathogenicity and sequence analysis studies suggest potential role of gene 3 in virulence of swine enteric and respiratory coronaviruses. Advances in experimental medicine and biology. 1997; 412; 317-321. [PubMed: 9192036].
