Phylogenetic tree and amino acid alignment. (A) Shown is the phylogenetic analysis of known actin isoforms from selected vertebrates numbers give the percentages for the Bayesian posterior probability. The accession numbers of the sequences used in this analysis are given in Additional file 1 and additional phylogenetic trees are given in Additional file 3. (B) The alignment of the amino acid sequences of the selected actins of human (Hs), snake (Am), zebrafish (Dr), branchiostoma (Bb), urochordate (Cs), fly (Dm), plant (At) and yeast (Sc) is showing the strong conservation of the sequence. The darker shading is used to indicate the more conserved locations. The colored arrows highlight the main sites which show a difference in the 3D protein model (Figure 3). The corresponding coloring of the protein and species name highlights which species show this difference in our 3D protein models.