Synteny and phylogenetic analysis of zebrafish abcb4 /Abcb4 and abcb5 /Abcb5. A) Conserved synteny of zebrafish (Danio rerio), green spotted puffer (Tetraodon nigroviridis) and human (Homo sapiens) abcb1/ABCB1, abcb4/ABCB4 and abcb5/ABCB5 regions. The human ABCB1/ABCB4 region is syntenic to zebrafish and green spotted puffer. The human ABCB5 region is syntenic to zebrafish and green spotted puffer; however, green spotted puffer lacks a abcb5 ortholog. B) The phylogenetic tree based on the multiple alignments (Clustal X2) of Abcb1, Abcb4, Abcb5 and Abcb11 amino acid sequences from Danio rerio and other vertebrates. The tree was generated using the neighbor-joining method and the percentage concordance based on 1,000 bootstrap iterations is shown at the nodes. Protein accession nos. (Ensembl or GenBank) are listed in Additional file 1: Table S2.