Additional file 9. Phylogenetic relationships among Gypsy clades. This tree is a simplified representation of Figure 9, in which annelid elements from the same clade are represented by compressed subtrees. All LTR-retrotransposons from a clade found in annelids are depicted in color. The reference Gypsy elements and Gypsy clades previously reported in the GypsyDatabase are in black. Node statistical support (>70%) was obtained through non-parametric bootstrapping using 100 replicates. (.pdf)