Gli/Glis/Nkl/Zic super-family phylogeny. A Bayesian consensus tree generated using the alignment in Additional File 1(see Methods for details). An independent Maximum Likelihood tree generated using PhyML had identical branching pattern at all major nodes. Bayesian posterior probabilities (black) and Maximum Likelihood bootstrap values (red) are shown for identical nodes. Genes identified in this study are demarcated by arrows. The protein families are identified at the node by coloured boxes and corresponding taxa are highlighted by coloured lines. The Zic family is demarcated by purple, Nkl by green, Gli by blue and Glis by orange.