FIG. 5.

Comparison of expression from the cap and IRES cistrons. On days 1 to 5 after transfection of BHK21 cells with either TBEV-bc mutant RNA or wild-type RNA, expression of protein NS1 (A and C) or envelope protein E (B and D) was determined by measuring the fluorescence intensity of cells stained using the appropriate monoclonal mouse antibody followed by a fluorescein isothiocyanate-conjugated anti-mouse antibody. The analysis of the IRES-A771C mutant is shown in panels A and B, and that of the 19-A, 26-A, and 45-A insertion mutants is shown in panels C and D. Each value is the mean from two independent experiments; error bars represent the range of values.