Fig. 6

Phylogenetic analysis of caspase domains identified in A. millepora. The phylogeny shown was calculated using a Bayesian approach (MrBayes) based on a ClustalW alignment of Peptidase_C14 domain sequences (for detailed information, see Materials and Methods). The dataset was also subjected to Maximum Likelihood analysis (Additional file 4). Posterior probability values are shown at each node, but at critical nodes, both posterior probability (black) and bootstrap support (red) data are shown as X / Y. Note that the ML tree differs somewhat in topology (see Additional file 4), so no bootstrap figures can be attached to some nodes in the Bayesian tree shown. Details of protein sequences used in the analyses are given as Additional file 7. Branch lengths are proportional to the number of substitutions per site in the Bayesian analysis (see scale bar in the figure). Background shading is used to emphasize relatedness of cnidarian and/or vertebrate proteins. Blue backgrounds underlie well-supported clades consisting exclusively of vertebrate sequences. Green background underlies the coral caspase-X containing 2 x peptidase_C14 domains. The dashed blue line demarcates a clade of cnidarian sequences that form a well-supported sister group to the vertebrate caspase-3/6/7 clade.Acropora millepora sequences are printed bold