Genomic Fossils Calibrate the Long-Term Evolution of Hepadnaviruses
Grey rectangles represent the different open reading frames of DHBV (GenBank accession number AY494851, isolated from a puna teal) encoding the precore (preC), core (C), polymerase (P), surface (preS and S), and regulatory HBx-like (X) proteins. eZHBVs (black lines) are labeled with letters as in Table 1. Group 1 and 2 correspond to the two groups of overlapping fragments used for the phylogenetic analyses (Figure 2). Asterisks indicate the occurrence of segmental duplication (see text). The white triangle in eZHBVl* indicates the presence of a 618-bp solo LTR belonging to the TguLTRK1b LTR retrotransposon family . The solo LTR is flanked by a 6-bp target site duplication (GCTCTC).