FIG. 9.

Effects of core promoter and precore stop codon mutations on replication of different HBV strains. MT5/6 (C to T at nt 1768 and T to A at nt 1770) and precore stop codon mutation (G to A at nt 1896) were introduced into replication-competent constructs (HBVayw strain) as described in Materials and Methods. These constructs were transfected into HuH-7 cells, and viral replication, transcription, and antigen expression were analyzed as described in Materials and Methods. (A) Viral replication. WT, wild type; SS, single-stranded DNA. HBs and HBeAg levels are indicated as signal-to-noise ratio (S/N). (B) Transcription of adw and ayw constructs. HBV RNA was purified from HuH-7 cells transfected with either adwR9 or aywR9 and analyzed by primer extension using a HBV-specific antisense primer (upper panel) or Northern blotting using an HBV-specific probe (lower panel). Transfection efficiencies as monitored by pTKGH cotransfection were similar among all samples.