Fig. 6

Determination of the origin of DVGs using MHV-A59 full-length genomic cDNA. (A) Diagram depicting the primer sets used for determining the synthesis of MHV-A59 DVGs in Figures (B)-(D). (B)-(D) Determination of the origin of DVGs using MHV-A59 full-length genomic cDNA. After assembly and in vitro transcription of MHV-A59 full-length genomic cDNA, the full-length viral RNA was transfected into BHK-MHVR cells. After 48 h of transfection, total cellular RNA was harvested (VP0), and the supernatant was collected to infect fresh BHK-MHVR cells. The virus passage step was repeated until VP2. DVGs were detected by RT-PCR with primers shown in Figure (A). bp, base-pair; M, DNA size marker; hpi, hours postinfection; m, mock-infected cells; sgm, sgmRNA N; gm, genome; VP, virus passage; 18 S, 18 S rRNA