ABSTRACT
Hepatitis B virus (HBV) is a major world health problem due to the high percentage of chronic HBV carriers, worldwide now approximately 200 million people, and the association of HBV with hepatocellular carcinoma, one of the most common human cancers. HBV has a very limited host range and infects only humans and chimpanzees, but in the last few years, related viruses have been characterized from woodchucks (WHV), ground squirrels (GSHV), ducks (DHBV), and others (for reviews on hepatitis viruses, see References 1 through 3a). Although mature HBV contains a DNA genome, its replication involves reverse transcription of an RNA pregenome. In this regard, HBV replication resembles that of cauliflower mosaic virus (described in the previous chapter) as well as the transposition of some eukaryotic mobile elements such as yeast Ty elements and copia-like elements of Drosophila (described in the following chapter). We should like to focus here on the processes involved in HBV replication via an RNA intermediate and to make a brief comparison of this replication strategy with those employed by other retroviruses and retrotransposons.
