Fig. 13

A Molecular phylogenetic reconstruction of the psammophiine lineage-specific derivation of the SVMP propeptide domain into a novel toxin family, with the subsequent explosive diversification of the cysteine-linked forms. Additional Files contain sequence alignment used for constructing phylogenetic tree (Additional file 23), tree output file (Additional file 24), and zoomable high-resolution tree image (Additional file 25). B Alignment of representative SVMP proproptide domains. Region shaded in grey is that which is homologous across all representatives, with the unshaded region indicating the location of the putative frame-shift mutation that led to the evolution of the new toxin family in psammophiine snakes. Cysteines are highlighted in black, secondary structure imparting prolines highlighted in red