Figure 2
From: Low frequency of paleoviral infiltration across the avian phylogeny
Phylogenetic tree of exogenous and endogenous hepadnaviruses generated using complete polymerase (P) protein sequences. Bootstrap values lower than 70% are not shown; single asterisks indicate values higher than 70%, while double asterisks indicate values higher than 90%. Branch lengths are drawn to a scale of amino acid substitutions per site (subs/site). The tree is midpoint rooted for purposes of clarity only. The exogenous hepadnaviruses are marked. A cartoon of a virus particle marks the phylogenetic location of an inherited hepadnavirus invasion. Avian host species names are used to denote avian endogenous hepadnaviruses and scaffold numbers are given in Table S2 in Additional file 1. All abbreviations are given in Table S9 in Additional file 1. HBV, hepatitis B virus.