Immunofluorescence analysis of BHK-21 cells transfected with wild-type EAV RNA or with mutants L3, B3, or LB3. (a) At 12 h posttransfection, cells were fixed and double-stained for nsp2 (Upper) and N (Lower) to test for genome replication and mRNA7 synthesis, respectively. (b) Double labeling for nsp2 (Upper) and GL (Lower) to monitor genome replication and mRNA5 transcription, respectively.