Kinetics of genomic and antigenomic RNA synthesis in JEV-infected BHK-21 cells. A. BHK-21 cells were infected with JEV at an MOI of 0.01, and cytoplasmic RNAs were extracted at the indicated time points postinfection and were subjected to Northern analysis as described in Fig.1. Oligonucleotide probe detecting 18S rRNA is shown at the bottom. B. Diagram of primer positions and the vector used for generating RNA transcripts as standards for real-time RT-PCR assay. C. The RNAs were subjected to real-time RT-PCR assay. Amounts of genome and antigenome per cell were plotted and calculated (C and D). Vertical arrow in panel C indicates the time when sfRNA becomes apparent.