Fig. 3

Phylogeny of deduced PSMB8 amino acid sequences from selected species. The evolutionary history was inferred by using the Maximum Likelihood method based on the JTT matrix-based model [75]. The percentage of trees in which the associated taxa clustered together (100 bootstrap trials) are shown next to the branches. The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. All positions with less than 95% site coverage were eliminated. Salmonid and Northern pike PSMB8 sequences originate from the haplotypes described in Materials and Methods with the exception of the Atlantic salmon PSMB8F sequence which is from GenBank with accession number in parenthesis. Zebrafish haplotype sequences are from McConnell et al. [31] and medaka haplotype sequences are from Hd-rR [43], HN1 [44] and cab [33]. Accession numbers are shown in parenthesis. Pseudogene fragments are not included in the phylogenetic analysis, but are included in Additional file 1: Text S1 and Additional file 1: Text S2. The tree is unrooted and some bootstrap values are not shown for clarity