Protein domain evolution of OVOL proteins from different metazoan lineages over a period of >700 MY.

<p>A highly conserved domain of a tetrad of C2H2 zinc finger motifs (red and yellow box) is found in various metazoa. Primarily, the N-terminal extensions in C2H2 lead to different types of protein with the exceptions of OVOL proteins from the leech and sea urchin where extension was found in the C-terminal end of C2H2 zinc finger motif. The ID segments with no homology in evolutionary distant organisms are marked in different colors. Times of divergence are taken from Kumar and Hedge (2003) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0039399#pone.0039399-BlairHedges1" target="_blank">[82]</a> and Ponting (2008) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0039399#pone.0039399-Ponting1" target="_blank">[83]</a>.