Figure 3C. Copyright: This image is from Vesque C et al., Cloning of vertebrate Protogenin (Prtg) and comparative expression analysis during axis elongation. [doi:10.1002/dvdy.20898] Dev Dyn 2006 Jul 31;235(10):2836-2844 and is displayed with the permission of Wiley-Liss, Inc. who owns the Copyright.