Fig. 4

Phylogenetic analysis of canine HBD and HBB genes shows gene chimerism between them. Maximum Likelihood trees were generated for gene segments from carnivores, with human and horse as an outgroup. a-g correspond to gene structure elements: 5′UTR (316 nucleotide positions were analyzed after complete elimination of gaps), exon 1 (92 positions), intron 1 (83 positions), exon 2 (223 positions), intron 2 (420 positions), exon 3 (125 positions) and 3′UTR (351 positions), respectively. Dog HBD1 and HBD2 genes are marked blue and dog HBB yellow. Abbreviations: 5′/3′ UTR500, first 500 bases of 5′ and 3′ untranslated region sequence; fer, ferret; pan, panda; hum, human. Tree branch lengths correspond to the number of changes per amino acid position (scale bar). Bootstrap values were generated from 500 repetitions. The same topology of the dog genes is evident using the Maximum Parsimony treeing method (Additional file 7)